Seriously, If I paid $100 to hear an artist sing a bunch of songs that made him famous; and if he didn’t sing them - I’d storm out and demand my money back.
I don’t care what religon he belongs to. When I pay upwards of $100 for a concert ticket, I have this little idea that the artist who is advertized will actually sing the songs he said he would - not a tribute band. This is about the audience, not the artist.
I don’t care what group, I don’t care what set of circumstances. If I pay to see KISS, Aerosmith, Styx or whomever - they had better be playing, or I’m walking and demanding my money back.
The people walking out had nothing to do with Islam; it had to do with them being cheated out of hearing what they were promised. The concert promo’s likely had clips of the songs that made him famous, so the audience has a reasonable expectation to hear those songs.
Now, if Yusef or whatever he calls himself now said “I will not sing some of my songs that made me famous, for my faith prohibits it; and the songs I will not sing are .....”; then the audience would have had warning.
Actually, you have to be careful of what you expect if you go see Styx these days, since the acrimonious break-up with Dennis DeYoung. Not only do the remaining Styx members avoid some of DeYoung’s popular ballads in concert but I also went to see a concert billed as Dennis DeYoung performs the music of Styx and not only does he avoid many of the hard rock Styx songs but I’d guess that at least half of his concert wasn’t Styx music and some of that was more Broadway than rock.