Anyone know about thier collaborations?

apparently, frank was a very big johnny guitar watson fan. while making the album "one size fits all in 1975", frank heard that watson was in the studio complex and invited him in, and watson did some outro vocals for the song "san ber'dino".
then much later on, in the mid '80's they hooked up again. on july 22, 1984 johnny guitar watson guested on stage in los angeles at one of frank's shows at the palace theater, and then again (probably in 1984) co-writing the song, "i don't even care" for the 1985 album, "frank zappa meets the mothers of prevention".