I don't know that 12", jb, but if it is the one quadruped mentions it likely is Carlos' Spread Out (which contains that line in the lyrics, Rock Dis Ya Music). Doubt Purpleman has two different takes on that riddim, so my guess would be it's the Spread Out / Boom It Up combo. Maybe quadruped can confirm later?
Somewhat belatedly, I've located the Shuttle 12" (SH002) and can confirm that Rock Dis Ya Music is Spread Out / Boom it Up.
The other side is listed as Rasta Vibration and is credited to Don Carlos & Mother Liza. It's actually Don Carlos singing "Ababa John I" followed by Liza doing something which is possibly called "Me Can't Tek Di Nowadays Man".
Apparently, there were at least two female deejays who used the name Mother Liza so I'm not sure if this is the same one who made those records with Kojak (Bam Bam, Sky Juice, Fist to Fist Rub a Dub etc)
Thanks again for the Purpleman mix, BMC. Keep up the excellent work.