You will need a work permit or run the risk of being deported.
Not strictly true... foreign artists and performers can work for up to 30 days from entry without a work permit (although don't ask me how its done paperwork wise!).
Manager: Ok Elton, before you do the Istanbul gig you gotta get a Work Permit.
Elton: Oh ok then, I'd better apply now as I wouldn't want to disappoint my fan.
JF