Bob Thomas

T he extended repetition of rhythmic or melodic phrases lies at the very heart of music and probably has been there ever

since our ancestors first discovered the pleasures of singing and dancing. Musical structures that combine repeating melodic and rhythmic elements became popular across all cultures not only because they are easy to memorise, but also because of their potential, under the right circumstances, to induce meditative and other transcendental states of mind.

These repetitive, rhythmic structures developed into a sophisticated high art in many cultures, but European art music, some time in the Middle Ages, started to take a different path. The development and elaboration of the rules of harmony that began during the Renaissance led finally to the great Classical works, where complex harmonic structures used rhythm and repetition simply as a landscape for the harmony to occupy. This resulted in the mode-based, repetitive, rhythmic, non-classical music of Europe and the rest of the world being labelled as ‘primitive’.

Ravel’s 1928 composition ‘Boléro’ is, to me, the point at which rhythm and repetition returned to centre stage, its two themes repeating nine times in 15 minutes as it builds to that climactic crescendo. In the early 1940s, composers such as Cage began using gramophone records with varispeed turntables to produce works based on pre-recorded music, and after the end of the Second World War, musique concrète composers like Messiaen and Stockhausen produced some works based on gramophone records. However, the availability of the tape recorder from 1950 meant that the earlier technology was quickly superseded. Edgard Varèse’s 1954 composition, ‘Deserts’, was the first of this new wave of music to use both the physical and electronic manipulation of tape to alter, reverse, edit, overlay and generally mangle pre-existing or newly recorded sounds in exciting new ways.

At the same time, on the other side of the Atlantic, a certain Lester Polsfuss (Les Paul) was also using the new tape technology to create new music but, although in many ways it was

no less complex than that of Cage, Varèse et al, his work was aimed at capturing and enhancing a performance of a popular song, rather than trying to create new works by reworking recordings.

No one actually knows when tape loops (from which our term ‘looping’ takes its name) were developed but it is likely that their genesis goes back to the inventors or the early users of the tape recorder. In any event, outside the world of avant-garde music, tape loops almost immediately turned up in radio and film studios the world over. However, tape loops are static in that once created, they can’t be modified ‘live’. It wasn’t until 1963 when the American composer Terry Riley was working in Paris on the recording of his music for the play, The Gift, that an anonymous engineer developed for him a tape delay/feedback system based on two Revox tape recorders that could be used live. This system, which Riley named the ‘Time Lag Accumulator’, and which became Robert Fripp’s 1970s ‘Frippertronics’, is the spiritual ancestor of

Line 6 JM4 Looper Digital looping pedalDigital looping pedal

Ever since the dawn of tape loops, musicians have exploited the ability to record a phrase and play it back again... and again... and again...

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the digital looping systems that we know today.For more mortal musicians in the 1960s and

1970s, the tape-based Watkins Copicat and the more costly Echoplex gave us a foretaste of what was to come from the digital world, but it wasn’t until 1986 that the legendary TC Electronics 2290 — the first digital device that was a real looper — ushered in the era of live looping as we know it today.

New, the TC 2290 was horrendously expensive, but things have improved dramatically in recent years as more cost-effective solutions have arrived, and nowadays one of the best-known and most effective examples of a musician employing live looping is KT Tunstall’s brilliant use of her Akai Headrush E2 delay/phrase sampler pedal on ‘Black Horse And The Cherry Tree’.

The new JM4 Looper isn’t Line 6’s first looper, as the DL4 Delay Modeler, released in 2000, had a 14-second loop facility, and the loop and playback engine first used in the Spider Jam combo provides the basic architecture of the JM4. Line 6, as we all know, are a company whose innovative, modelling-based products have been taking the world by storm since they started up in the mid 1990s with the aim of harnessing technology for the benefit of guitarists. With the JM4, Line 6 have taken the engine first developed for the Spider Jam combo, and have added a number of looping-related features and facilities that I haven’t seen before.

How to drive itThe JM4 is housed in a cast, greyish-brown metal case crowned by a fair number of heavily chromed knobs and switches. If you’ve played with the Spider Jam, you’ll find the controls of the JM4 instantly familiar. The front panel splits conceptually into three areas: the loop/playback controls, the knobs relating to the amp models and the four footswitches that handle, in addition to several other functions, Record, Playback and Undo.

Inputs and outputs sit on the back panel. Starting from the left, you’ll find the Input jack for your guitar, which has its own dedicated amp modelling and effects processing. The XLR socket and its associated Trim control for a (non-phantom powered) microphone or

other balanced source comes next, and it feeds independent EQ and effects processing. Next you’ll find the mono Aux input, which can be used for almost any kind of input (second guitar, bass, keyboard, drum machine, etc), and this can be processed and recorded using either the guitar’s or mic’s effects. The last input is a stereo mini-jack which lets you feed any stereo source into the JM4 for recording as part of a loop or for playing along to.

The main JM4 outputs are made up of a mono jack Out To Amp socket and a pair of mono jacks giving you a Stereo Line Out for connection to a PA system or recorder. In what Line 6 call Normal operation, guitar and any loop playbacks etc are fed to all jacks, but in Performance mode, only the guitar is present at the Amp output, with everything else turning up on the stereo jacks. The last output is a stereo mini-jack headphone output, which, when used, forces the JM4 to return to Normal operation. The unit’s overall output level is controlled by the rear panel Master Volume.

The back-panel complement is completed by the SD card slot, which takes standard SD cards up to a maximum capacity of 2GB. You can use the card to store JM4 Looper recordings and to transfer them to and from your computer. This ability to create, record and then export loops, modify them externally and then re-import them is a significant step forward for looping.

On the front panel, the middle row of controls for the 12 amp models are pretty much self-explanatory, with the selector, drive and EQ controls operating as expected. The effects are limited to one knob selection and level control of Chorus/Flange, Phaser and Tremolo, a second operating similarly for Delay, Tape Echo and Sweep Delay, and a third dedicated to Reverb. Delay times are set using the Tap button that you’ll find on the top right of the front panel, where it also selects the Tuner function when held. Finally, the Channel Volume allows you to balance the volumes of different setups when you store them in the 36 User preset locations. In case you think that that isn’t that much storage, you might like to know that the JM4 comes factory-loaded with a comprehensive collection of guitar amp/effects combinations made up of over 200 artist-created presets and over 150

song-based presets for your sonic enjoyment. It’s the 71 songs and 86 drum patterns that are

factory loaded into the JM4 Looper that really make it a looper’s paradise. Recorded by real, live session players and seamlessly and endlessly looped (you can turn this off), these form a great basis for jamming along to, or as the basis for your own songs and loops. When you load a song or drum pattern, the JM4 automatically loads a suitable guitar amp/effects preset (this too can be disabled) and you’re good to go.

The top set of front-panel controls looks after the selection and setup of loop playback and recording. The back-lit, orange, mid-row matrix display keeps you informed of what you’re up to and, on its right, the large Select knob and the four-way navigation button let you find your way through the menus and modify values. The Save button that sits next to these lets you store amp/effects setups, save recordings and erase saved recordings.

The four buttons on the left of the display are seriously multi-functional. The Record Select button toggles between Guitar and Mic/Aux inputs, but hold it and it lets you choose whether the Aux input reaches the recorder via the guitar amp/effects or through the Mic effects. The Song/Drums button lets you select playback from a factory song or drum pattern, or from a user recording/loop stored on an SD card or the JM4 itself. A second press brings in, among others, the Time Stretch/Transpose and Speed/Pitch Adjust functions. The Level/Inputs switch brings up playback levels for Song/Drums, Guitar and Mic/Aux tracks, while a second press lets you set Mic, Aux and CD input levels. The Tones/Settings control has the most options of all, giving you on first press direct access to the Style, Artist and User guitar presets, then the Mic/Aux presets on the second press and finally another nine functions including Mic/Aux EQ, Delay/Reverb and Compressor, plus six setup settings.

Finally, as this is a floor-based unit designed for live use, four footswitches let you actually drive the thing. There are five footswitch modes: Jam Control, Loop FX, Rec Select, Guitar Preset and Guitar Amp/FX. In all modes the extreme right-hand footswitch is used solely for mode selection/exit, with the other three controlling

Multiple input sources are catered for, along with flexible output routing options.

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Once you’ve got your synchronised loops, you can then import them into your computer and overdub, add new material and generally be creative knowing that you can then re-save them as WAV files and load them back into your JM4 where they will loop and (as long as you haven’t changed the length) lock perfectly with the original reference loop. Now that’s what I call a killer app, and probably one that Varese and Cage would have killed for!

ConclusionI’ve been playing around with tape loops and loop-based music for longer than I care to remember. Having started out with physical tape loops, in recent times my looping has been primarily computer-based and, frankly, not that high up my list of musical priorities. The Line 6 JM4 is set to change that.

I haven’t really found anything about it that I don’t like. I could have a whinge about the fact that, once you’ve selected a song from the library list, the display doesn’t automatically revert to the main Song screen so that, without having to bend down and manually press the Song switch, you can immediately see what key it is in. Continuing in minor moan mode, I could also question why Line 6 don’t include the songs’ chord sequences in the manual; why the numbering of the JM4’s song and drum library lists are so wildly non-sequential; and why the Advanced Manual is only available on-line.

However, none of these are actually of any importance. The real-world reality is that the JM4 sounds great, is easy to use live or in the studio, allows you to export and import WAV files to and from SD cards, and the potential of 6.5 hours recording time on a 2Gb card means that you can build up an enormous library of loops and recordings that can be cycled and recycled virtually forever.

If you’re into looping and you’ve heard of it, you’ve probably already been out and bought a Line 6 JM4 Looper. If you aren’t or you haven’t, just go out and buy one. Given its feature set, facilities and retail price point, there’s really nothing more to say.

playing skills. Each song displays its basic key signature on its title page and changing pitch and/or tempo is the work of moments. The onboard memory is sufficient for a maximum of 100 individual recordings totalling 24 minutes, so once you’ve recorded your loop you can then save it, which will also store the pitch/tempo setting, the Aux setup, mic effectss and the guitar preset used. Again, all these functions are really simple to get to and to use.

The quality of sound that you get from the JM4 is very good and I would have absolutely no hesitation in using one on stage or as part of a studio session. I particularly liked the separate guitar output for direct routing to an amplifier — such a useful facility.

If all that the JM4 gave me was a bunch of jam tracks to play along with and the ability to build up, record, save and recall an infinite number of loops (SD card purchase budget permitting), I would consider it to be the biggest bargain in the looping world. However, the JM4 has a trick up its capacious sleeve that, for me, is its real raison d’être.

Recordings saved on the JM4 are saved in a proprietary format named JAM. Essentially, a JAM file is a folder that contains a Guitar track, a WAV/Mic/Aux track and a ‘track’ that contains all the settings for the recording. In addition, the JM4 can create (through its Save Rec Mix As WAV function) mono 16-bit WAV files on, and load them back from, an SD card. It is these two latter abilties that make the whole thing so exciting.

Saving a Rec Mix as a WAV lets you adjust the relative levels of the three replay tracks (Song/Drums, Guitar and Mic/Aux/WAV), which means that you can create three solo and completely synchronised WAV loops by turning down two of the three tracks each time you save the recording as a WAV to the SD card. If you then reload a WAV, you can overdub another guitar track, mix that down ‘solo’ and you’ve got yet another perfectly synchronised loop at your disposal. Workflow is crucial in making all this synchronised loop creation work and the JM4 Advanced Manual (available only on-line) gives you the blow-by-blow lowdown on how to achieve this.

mode functions. Jam Control is the default and lets you play songs/drum patterns, record, play and overdub loops and undo errors and clear unwanted loops. Loop FX mode simply lets you play back the selected loop at half speed. Rec Select enables you to step through your previous recordings to select one for playing along to, and to toggle Guitar or Mic/Aux input for recording. Guiatr Preset steps through Presets and gives you footswitch access to Tap time and Tuner activation. Finally the Guitar Amp/FX mode lets you individually bypass the selected preset’s amp model, modulation effects and delay effects.

In useThe JM4 is, in reality, ridiculously easy to use. Plug in your guitar and an amp or headphones, select a song to jam along to, adjust the levels so that you can hear what you want to hear and jam away to your heart’s content. Fancy creating a loop? If you want drums on it (you can record a loop without one), just pick a drum pattern to play along to, select Guitar as your recording source, hit the Record footswitch, listen to the count-in (only there if you’re using drums), play as long as you want your loop to be, hit the footswitch on the first beat of the next bar and that’s you done. If you don’t like the result, hit Undo and start over, otherwise you can overdub another guitar or use the Mic/Aux inputs to add different sounds. It really is that easy to get started!

If you want to get a bit more into the JM4, you can change the key and tempo of the pre-recorded songs to better suit your voice or

JM4 Looper 200+ artist-created presets.•

150+ song-based presets.•

36 user-programmable presets.•

12 Line 6 amp models.•

Seven Smart Control effects.•

Three Tone controls.•

Integrated tuner.•

Independent Mic/Aux input effects: •

three-band EQ, Compressor, Delay and Reverb 100+ Endless Jam tracks and drum •

grooves. 24 minutes of 16-bit/44.1kHz internal •

recording time. SD card slot for importing and exporting •

loops and recordings (maximum 2GB). Record/Overdub, Play/Stop, Half Speed •

and Undo footswitches. Quarter-inch instrument input.•

Quarter-inch aux input.•

XLR mic input with Trim control.•

3.5mm CD/MP3 input.•

3.5mm stereo headphone output.•

Quarter-inch guitar amp output.•

Quarter-inch stereo outputs.•

Dimensions (WDH): 305 x 190 x 83mm.•

Weight: 1.8kg.•

Tech Spec

Line 6 JM4 LooperDigital looping pedal

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This article was originally published in Performing Musician magazine, May 2009 edition.

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