Part four of this epic saga of detuned strings already, and this is the bit where Jakko Jaksyzk goes on about the Harry Cole trem and the Micro-fret Calibrato, which perhaps shouldn't be the obscurities they've turned into. On the way, our resident wanger meets Jimi Hendrix (here) and Mark Farner of Grand Funk Railroad (over there). You win some, you lose some...

By the mid to late Sixties a lot of aspiring guitarists were getting bored with tremolo arms. They foolishly thought that it had all been done. Their Shadows LPs were firmly placed at the back of the pile, Bigsby springs could be heard clanging into bins, and Vibrola arms were being snapped off and lobbed out the window. A definite ebb in wang bar popularity was being experienced.

So I can't help but feel that because of this fickle bunch of hippy guitarists ignoring the wonderful world of whammy bars a lot of potentially good and creative ideas became lost. Young Jimi Hendrix was flying the flag in the most extraordinary fashion, but his influence on his contemporaries took time to filter through.

Incidentally, those of you waiting expectantly for a Best Of Hendrix Tremolo Excursions list will be used to my monthly fudging of the issue. Thing is, virtually everything he recorded is worth a listen. He was really the first player to utilise the arm's ability (on a Strat, anyway) to detune the guitar to excess. Doing this at high volume created feedback which in turn was bent around like crazy by his trem technique.

Hendrix is surely the grandfather of modern tremolo histrionics, be they Allan Holdsworth's subtle variations or Eddie Van Halen's wonderful over-the-top style. Both will admit to Hendrix's inspiration.

Still, I digress. I was about to point out some of the sad losses to the tremolo arm world. An idea that had been knocking around the workshops of the wang bar designers for some time was that of a trem which detuned each string by the same amount. What am I talking about? OK, let me explain.

Vibrato users among you may have noticed that when you depress the arm (playing along to one of my records, for instance) the lower strings become slacker a lot faster than the higher ones. By the time your top E has been detuned a minor third, say, your bottom E will be dangling off the fretboard. So if you play a chord and then whack the arm down, the whole thing will soon become a harmonic mess. Consequently the idea of an arm that could detune a set of notes by the same interval was wracking the brains of many a guitar maker. To my knowledge only two such devices ever saw the light of day.

The lesser-known of the two "calibrated" vibratos was designed by a Mr Harry Cole back in 1963. In Harry's unit each string essentially had its own tremolo system: each string had its ball-end held in a hook-like extension of a rectangular block which pivoted on an axle. The block had an Allen screw for adjusting its pivotal movement in relation to an axle passing through all six blocks. For goodness sake concentrate! Otherwise you'll never understand. I know it's difficult to work out what's going on exactly, and I'm the **** that's writing it.

OK, when you've digested this explanation you'll realise that because of the cam-like action when the spring is depressed, the amount that the strings' tension changed was independently variable for each of the six strings. There was one large spring located behind the bridge-pieces; its downward tension on the rocking bridge was adjustable with a spanner.

To increase further the chances of the unit staying in tune, Cole designed a bridge with six pivoting saddles. As the tension of the strings was relaxed or increased, the saddles rocked forward or back, so as to avoid the strings' windings getting caught and pulling the whole thing out of tune. There was also a large plate placed under the spring and over the trem's mechanism to create a fixed stopping point for the unit. Like the Fender Jazzmaster's Tremlok, this was intended to prevent detuning of the remaining strings if any one string broke.

The Cole tremolo was sold in the mid-Sixties as an accessory and was available for most types of guitar. It virtually sank without trace, however, which seems a great shame.

The other vibrato doing the same job was to be found on a range of guitars called Micro-frets. These were made by a small company which produced some eccentric guitars. Their home was in Maryland (the home of Harry Cole, incidentally), and their guitars were original machines which were not particularly successful. Try as I might I can't find one. I've been looking for one to give the old once-over for months — no success. I do have childhood memories of a band called Grand Funk Railroad playing Micro-fret guitars — at the time Grand Funk were purported to be the loudest band in the world.

What with that reputation and the tendency for critics to pan them mercilessly for their crassness and lack of knowledge ("Buy them a chord book" etc), Grand Funk Railroad can't have enhanced the popularity of the Micro-frets range as their most famous users.

However, the Micro-fret Calibrato vibrato, as it was known, does have a fine reputation. People I've spoken to who've used them say they worked well and were made to a high standard. The effect was apparently much the same as the Cole unit, keeping the notes in relative tune when lowered by the bar. (Any Micro-fret owners: please get in touch with me via the magazine. I'd still love to try one.) This calibrated idea seems a damn good one to me and I'm surprised that no-one has resurrected it in the light of the trem's current revival. I'm sure that even as I write someone (doubtless Japanese) is beavering away on this device. If they are, then I for one would very much like to see it.

Well, this month's article is a little shorter than normal. This is not because I've run out of info — far from it. But it's not always possible to try out all the devices and examine them in-depth in time for the next issue. That, plus the fact that as a working musician it's been a bloody busy month for me.

In the next instalment I'll be following the guitar's endeavour to emulate its cousin, the pedal-steel guitar. The calibrated vibrato helps here to some extent, being able to bend chords down. But devices like the Bigsby Palm Pedal and the Parsons/White B-Bender became much used by country players. I'll also explain the workings of a complicated pedal-controlled string bending device for the standard electric designed by country guitarist Phil Baugh. So don't you miss it.