Singer Peter Gabriel refused to join his former band Genesis on their 2007 reunion tour because he was "too busy". The 57-year-old shot to fame with the group in the 1970s but walked out in 1975, clearing the way for drummer Phil Collins to take over lead vocals. Genesis reformed last year (06) for the 2007 World Tour but Gabriel's hectic work schedule meant he was unable to get involved. He says, "I don't have any ideological objections, it's just at the time it was expanding (and) I had other things I wanted to do. "You have to think twice about making a big time commitment to something that is backward looking."