Pursuant to a recent post....
Maaseh-shahaya...
A certain Talmid Chochom entered a yeshiva in Bnei Brak one Thursday night with a guitar and started playing Carlebach songs with the boys. Someone heard what was going on and ran to a famous Rov in Bnei Brak to complain about this terrible breach of custom. Instead of learning gemara with tosfos, the boys were having a kumzitz playing the music of a man with longish hair!!
The Rov said "I don't know who Carlebach is, I don't know what a guitar is, but if a yid is willing to take off his frock and sit with the boys and give them chizzuk - I envy his olam haba..."