ZD:
Apples and oranges. We don’t even know who composed most niggunim. Singing them says nothing about the composer, and is certainly not an endorsement. It is related that the Viznitzer Rebbe from Monsey ZT”L once heard a nigun that he liked, and he asked that it be sung for him again several times. Someone approached the rebbe and whispered to him that this was composed by R’ Shlomo Carlebach. The Rebbe answered, “Nu, er lozt nisht?” (So, he doesn’t allow it?) And they were instructed to continue singing it. The problem with the nigun from the rock star is that it has no Yiddishe taam. It sounds like goyishe music, and that would be abominable, very inappropriate for a shul. You cannot make that comment about Carlebach nigunim.