Where are the new movie themes ?

In the not-so-distant past, every summer blockbuster had to have its own chartbusting theme song.
Bryan Adams did everything he did for Robin Hood; Whitney Houston would always love her Bodyguard; Celine Dion's heart, she assured us, would go on, despite the sinking of the Titanic.
But, musicals like Mamma Mia! aside, recent blockbusters have been bereft of big-name ballads. From X-Men to Pirates of the Caribbean, there isn't a power chord in sight.
Most striking of all is the complete absence of rock music in the rebooted Batman franchise.
Hans Zimmer, who co-wrote the soundtrack for Batman Begins and The Dark Knight, says his vision of Gotham City has no room for the likes of U2, Prince and R Kelly.
"There was never any doubt that we were going to be songless," says the Oscar-winning composer.
"And, trust me, we were flooded with requests from every band in the world. I actually had to say no to some really interesting people."