Regardless, it was a pretty fun watch.
It made a good effort at being dramatic while never quite taking itself seriously, ready to throw in a dumb joke or two to remind you what anime you're watching.
Its art was acceptable. It didn't do anything very memorable, but its sometimes bizarre character designs and a few interesting CG moments (mostly) prevented it from being boring.
The characters remained almost entirely one-dimensional throughout the show, with any developments in their attitudes or actions being heavily predictable. However, since their base characteristics (i.e. being rebellious rock stars) were enough to keep one's interest, it wasn't really that much of an issue.
All of the above, particularly the premise itself, would have probably landed this anime a 7 in my book. Unfortunately, the show takes a hit with what I see as a glaring fault: what they were playing was barely even rock. I was extremely disappointed with the music in this show. The entire plot is based on the rebelliousness, soul, and passion of rock n' roll, yet many times it was hard to tell the difference between the protagonists' music and the pop-idol music they were fighting against. The "rock" of Bakumatsu Rock was the most simplistic, light-edge, vocal-centric version of the genre they could have used, which certainly isn't at all reflective of the spirit of rock. From the first time the main character played a song, my enjoyment took a huge plunge. I had gone into the show expecting to hear great music battling bad music, creativity battling standardization, excellence battling mediocrity, individuality battling the hive mind. Instead, my ears were met with two "different" styles of music battling to the same tune. Pop-rock versus pop hardly makes for an epic encounter.
That being said, the show still managed to be entertaining. It also had some parallels between its fictional government-controlled music scene and the music industry we have now, though the lessons felt rather hollow in the face of what music was being presented as artistic. All-in-all, Bakumatsu Rock was worth watching if you don't really have anything else to watch, and are craving to watch a show wherein pop-idols get what's coming to them.
Just don't expect any Foo Fighters.
