Just read on MSN website somewhere they have listed the top 10 phony rock bands. Actually how do you define a rock band? The author of the article established few set of characters that rock bands should have:
1. No solo acts allowed
2. No bands existed before their big-screen debuts
3. Rock and pop groups only — no jazz combos, classical quartets or swing bands
4. The bands perform on-screen, even if only lip-synching or pretending to play their instruments to pre-recorded track
5. They produce arguably good music

So based on these criteria, the following bands are not a rock band:
Spinal Tap, Pop, Stillwater, The Bang Bang, Strange Fruit, The Venus in Furs, The Wonders (previously know as OneDers), Max Frost & the Troopers, Eddie and the Cruisers, and The Committments.