A band's most disappointing album, as this list shows, isn't always a band's worst record. More often, they arrive at the end of a period of creative momentum or rebirth. They're also found at those times when rock's biggest bands took the first stumble toward a period of prolonged struggle or even into irrelevancy.

Sometimes a key group member or producer leaves; other times, the reasons for these disappointments are harder to pin down. Personal issues might come into play, or maybe an act begins to drift apart. But the results are the same: albums that didn't live up to expectations.

That leaves each of these disappointing releases with its own distinct legacy. Some work as career signposts for that moment when nothing was ever the same again. There are no small amounts of examples in which a disappointing album is also an artist's final commercial gasp. But for others – like Aerosmith, Bob Dylan, Paul McCartney, Robert Plant and U2 – disappointing albums were just another roadblock to be driven over or around.

As you look through our list of Most Disappointing Albums: More Than 100 Times Rock's Biggest Bands Let Us Down, you'll see a host of reasons why creative fortunes rise and fall. But whether it was simply a temporary setback, or a signal that things would get much worse, every one of these albums was a huge disappointment.