It was during The Rolling Stones' 1969 US tour that Keith Richards was first spotted with an unusual guitar.
The double-cut apparition featured a body made of polymethyl methacrylate, a tough acrylic thermoplastic marketed under brand names such as Lucite, Plexiglas and Perspex. Designed by luthier Dan Armstrong, the guitar was initially known as the 'see-through' for obvious reasons. These days, it's better known as the 'Plexi'.
In 1968, Dan Armstrong - father of pickup guru, Kent Armstrong - was hired by US manufacturer Ampeg to give its existing guitar and bass range a good kick up the arse. Hatching a plot to produce an instrument with serious sustain and futuristic aesthetics, Armstrong opted to spec plastic as a body material instead of wood.
The innovations didn't stop there. The guitar's bolt-on maple neck featured a then-revolutionary 24-fret rosewood fingerboard, while Formica sheets - doyen of cheap kitchens - made up the faux wood scratchplate. The single Bill Lawrence humbucker could be installed and removed in seconds. Why? Well, Ampeg offered six pickup models of varying output to allow owners to customise the guitar's tone as fast as they could swap them over.
In truth, while Plexiglas provided impressive sustain, it wasn't a great substitute for tone woods. It was left to the pickup to hold up the lion's share of the tonal end - and there was no shortage of disciples of the guitar's trademark throaty roar.
Besides Keef and his Stones bandmates Ronnie Wood and Bill Wyman (the latter whacked a bass version), Joe Perry of Aerosmith, Black Flag's Greg Ginn, Sir Paul McCartney (who owns the only left-handed example) and Dave Grohl are also notable Plexi junkies.
While Fender and BC Rich experimented with Plexiglas guitars, Dan Armstrong's iconic real deal was finally rebooted in 2006, 35 years after Ampeg discontinued the line, and two years later, Ampeg added the mahogany bodied AMG series, using the same outline.
However, it's the see-through monster that still bags the limelight. Featuring a few tweaks to update its performance (such as an intonatable bridge and better tuning stability), the sexiest part of the Plexi spec sheet remains as transparent as ever.
Dan Armstrong Timeline1969
Ampeg launches its Armstrong-designed 'Plexi' guitars
Production of the guitars ends... for now
A short run of Plesi reissues is produced
Armstrong's see-through classic is officially re-issued by Ampeg