Steinski is back on the air. The influential New York DJ, born Steve Stein, is best known for records that can never be released because they pose unclearable sample problems — the R&B, funk and soul mash-ups Lessons 1-3, which mapped out a jumping-off point for “turntablist” artists like Cut Chemist and DJ Shadow, and “The Motorcade Sped On,” a dramatic, riotous collage of audio clips referring to the assassination of John F. Kennedy.

His radio show, A Rough Mix, has returned after a 10-year hiatus to New Jersey freeform station WFMU, where it will air on Thursday nights at 7 p.m. throughout the summer. For the first installment, Steinski raids a friend’s record collection to dig into a series of old production music libraries from Great Britain known as the “KPM 1000 Series,” or the KPM “green sleeves,” owing to their distinctive cover design. Turns out some of these records are surprisingly funky and soulful, and have provided inspiration and source material over the years for any number of sample-based hip-hoppers.

You can hear what the show sounded like by visiting the WFMU archives for an MP3 or RealAudio stream. Who ever knew music libraries would have such a vigorous shelf life outside their intended domain? And who knows which of today’s library CDs some eccentric DJ may be spinning, 40 years hence?