tom trapp 

	steve vai: sound theories vol.I & II     (2007, 2cd, usa, favored nations)
	steve vai: visual sound theories: live with the holland metropole orkest     (2007, dvd, usa, epic / red ink 88697 06155 9)
	fuse: studio     (2016, cd, nl, fusemusic fm1601) - incl. 'echidna's arf (of you)'  (frank zappa)
	mats / morgan: live with norrlandsoperan symphony orchestra     (2018, dvd / 2 cd, sweden, morgan records .rec 003) - incl.zappa licks in 'sylox'