Tempo lock
When it comes to classic synthesisers, we are pretty au fait with the usual strong contenders, but what makes the original Roland SH-101 so interesting, is that it was never really a classic of its time, being a cheap and cheerful substitute for the more expensive machines. Thankfully, time has been exceptionally kind to the humble 101, being quickly scooped up as a bargain-basement secondhand purchase, back in the late 80s, before becoming a firm staple in production sound, throughout the 90s and beyond.