Rock Band is excellent and I love it, but the progression curve on BWT is not well executed for new players. BWT is the "campaign" mode of Rock Band.
This is not another "Remove the Fan Cap" thread.
You buy Rock Band and have a friend, family member, or significant other join you who isn't very skilled at the game. They will play off and on with you so you will likely do BWT because they want to complete the "story". They may or may not do any of the solo paths because they probably only play the game with you at your home.
It's very reasonable to expect a brand new player to have to do 30-40 songs before moving from easy to medium on guitar or drums. That was the progression path in the campaign for Guitar Hero and I think about what it took me and a friend to go from easy to medium on that game.
In BWT on Easy, the fan cap will be reached after only a few sets (I think we reached ours in 7). Fans are the second "motivator" you see after completing a song (the first being stars).
You quickly begin to see challenges for "more fans, less money" but you are already capped out so it doesn't make any sense to new players.
You see messages from your manager telling you to need more fans to have a world tour, but after completing songs it tells you you need to play at a higher difficulty to get more fans. You start seeing these messages after completing only around 10-15 songs.
Many of the early challenges such as the jet that appear very quickly in the starting and medium venues of new cities are fan capped.
You start accumulating "grey" challenges that have random songs in the setlist. Once the new player manages to progress to a few of the starter songs on medium and raise their fan cap, all of the "grey" challenges are now open and require medium or higher. With the random songs in those setlists, new players to medium difficulty can have far too advanced songs given to them instead of progressively difficult songs. We got "Won't get fooled again" on a new medium level drummer. He failed out very quickly and very frustrated, we got the "fans lost" message on top of it.
The learning curve for new drummers seems to be much steeper than for new guitar players, while many new players can advance vocals from easy to medium within just a few songs. This causes players in a band to advance at different paces and can be frustrating for new players.
The progression curve in Rock Band's "campaign" seems to be better designed for medium level players than for easy. The various setlist challenges pace well as cities are unlocked, and fan cap restrictions are much farther into the game.