Back by popular demand, another signal your favorite band is dried up and tired:
Suddenly Discovering World Music
The list of people who've gone down this road when the well has run dry is long and blood-soaked: David Byrne, Sting (not that there was much there to begin with), Peter Gabriel, Paul Simon. My proprietary models tell me there is an inverse relationship between the number of random Africans onstage and the number of times the song is worth listening to: the more random Africans the fewer times you need to give the tune a spin.
The convenient thing about resorting to world music is that because it involves Third Worlders, people are too scared to criticize it. God forbid they admit to not enjoying balafon solos. Political correctness dictates they must pretend that when they go to see Paul Simon - who built his fanbase with decidedly whitebread songs like "I Am a Rock" - they are pleased to see him making his concert a UN summit.
Doing a "brave" crossover into world music is a great way to shield yourself from bad reviews and lower listener expectations for your crappy new songs, because hey close minded guy...demanding melody is so Eurocentric!
Here's a tip: If you're at a concert and the singer suddenly says: "Ladies and gentlemen, I'd like to introduce my backup band: Kenya," RUN.