Only a handful of bands have retained the same line-up from beginning to end. For everyone else, personnel changes are a fact of life.
Artistic chemistry is perhaps the easiest part of the puzzle. Finding someone you can live with, in the studio and on tour, potentially for decades, is much harder to deal with. Then, of course, real life can and will throw curveballs, leading to a new round of “musical differences” that caused the previous line-up change.
