An older Aerosmith still working through tensions

The rock music world is notorious for its bickering but Aerosmith belongs to another category altogether - a band with constant and open tensions that has nonetheless managed to stay together.

The friction between guitarist Joe Perry and singer Steven Tyler shows no signs of mellowing with age, with the two Boston rockers both releasing tell-all books that portray each other in a less than flattering light.

Since his memoir Rocks came out in October, Perry says he has only exchanged text messages with his bandmate of 40 years.