These days I have started to listen Nusrat Sahib alot and I recommend all of you to listen this great man.
Honestly, what was it about this performance that you liked? Was it really the singing of Ali Khan and the composition of the song? Or was it the atmosphere of the occasion?
I thought the singing was competent but not terribly 'professional'. I can't really comment on the lyrics, except to say that a song without religious absolutist sentiments will beat a 'holier-than-thou' song any day of the week. The music was catchy, but I find it hard to believe that it represents a pinnacle even in subcontinental music, let alone in music generally.
Personally I think Freddie Mercury was the greatest singer I ever heard. As for composers, that is more purely a matter of taste. My current favourite is Ben Folds.