I remember an interview with James Blake (I think it was on Mylarmelodies exceptional "Why We Bleep" podcast), where he talked about Mutable Instruments Yarns for some tempo detection via Midi
-- Progspiration
I was interested in this because I have MI Yarns and I watched this interview. It's indeed Why We Beep with James Blake and at time 1: 06 :00 they discuss the Yarns.
I paid 170 € including shipping for a second-hand Yarns last year and there's better deals here on Modular Grid at the moment.