Debut albums are usually the best songs the band has. They have been road tested, and when it comes time to hit the studio, they pick the best 10 or 12 or whatever. The second album is usually made up of the songs that weren't good enough for the first album, or else, if they write new songs, then they don't have as much time to develop those songs as they did the earlier ones.
Boston in particular (or Tom Scholz, at least - who was the principle songwriter) had a hard time making this adjustment to be a full time band in the album-tour-album-tour sense. That's why he told the label up front that Boston's third album wouldn't be rushed out the way "Don't Look Back" was. Of course even Tom didn't realize at the time that it would take 8 fucking years to make "Third Stage" and lose the rest of the band (apart from Brad Delp) in the meantime.
He should have given up more control to the other band members. Brad Delp and Barry Goudreau could have written some songs, as they ended up doing without Tom anyway....
http://www.youtube.com/watch?v=1pWpZjMrJaQ Decent song, despite the chewed up video tape it came from