@aaronpk
Hm, my English isn't the best, but I would agree with the translation “Very little night music”.
"Quite small night music" would be more like "Ziemlich kleine Nachtmusik" (smaller is still possible). Yet sometimes "ganz" is used like "quite". I'd say "Ganz ok" for "Quite ok", but "Really great!" for "Ganz toll!". I don't think "really" could be replaced with "completely"?
Erm, maybe someone else has a better explanation. Thinking too much about it, ganz becomes a strange word :)