Bands toured like crazy in the 70's. Led Zeppelin II was written and recorded on the road. (technically that was the 60s, tho) I think you have the causality

Bands toured like crazy in the 70's. Led Zeppelin II was written and recorded on the road. (technically that was the 60s, tho) I think you have the causality backwards. Because CDs were a longer format, they enabled bands to take longer tours before having to release another album.