This is absolutely one of my favorite recordings by Zappa.  I refer to it as his "big band" album, partially because of the size of the band he's using here (at least 8 and at most 20 members), but also because of its strong jazz leanings.  Of all of the recordings that I own of Zappa's this is the one that feels the most like a jazz recording.  All of the songs besides For Calvin are instrumental and feature extended brass and woodwind solos.