Complex sentence: Zappa's own studio, the Utility Muffin Research Kitchen, built as an addition to Zappa's home in late 1979 was used to record and mix all of his subsequent releases.
Split into simpler sentences: Zappa's own studio, the Utility Muffin Research Kitchen, built as an addition to Zappa's home. Completed in late 1979, it was used to record and mix all of his subsequent releases.