Although "Beck" is an older anime (2005.) that I would have usually watched without any second thoughts (daily life, great rates, classic, compared to "Nana", etc.) for some reason I long resisted it. I am happy that I have rectified this mistake now.
"Beck" is anime telling a story of members of the band with a same name, during several (two or three) years of life of Yukio Tanaka, nicknamed Koyuki. At the start of anime, Koyukio is 14 and still in his middle-school, without any goals or talents in life. After accidental encounter with Minami Ryuusuke, a few years older guitarist who spent childhood in USA, Koyuki enters the world of music and rock, and we follow them and their personal life as they try to establish themselves...
I have always liked anime that depict daily-life of characters, shounen seined and josei. "Beck" is such combination that plays on the line between shounen and seinen. In this respect it is similar to "Bakuman" (or vice versa), and I think that fans of "Bakuman" will also like "Beck". By this, I mean that even though they are focused on shounen audience, the anime doesn't follows a typical maxim "if you just want something really hard, you can do it" that is, for me, the most distinctive trait of shounen anime. On the other hand, "Beck" has some ridiculous premises, which are strongest evident in later stages: their decision to stick with Chiba is totally illogical and impractical; also, wouldn't a band need to have more than three songs. One more thing I liked about this show is that it doesn't idealize teens - they are spiteful, promiscuous, drinkers, they swear (there is a lot of English curses)... There are some usual shounen characters like a bully or spoiled rich kid that compete with main characters, but there's more than that, also.
"Beck" has a very slow start - for first two episodes you have no idea what is happening. Plot goes very slowly, but the show has a really great build-up of characters. Most focus is put on Koyuki, and his relationships with other characters, but Ryussuke also gets his almost individual sub-plot. I noticed that plot sometimes get a bit rough - maybe they had to skip some elements from manga to fit it into 26-episodes anime. Curiously, anime incorporates lots of characters from out of Japan, but not in a way of the usual transfer-student. There is a lot of humor here, including some slapstick, but most of it is light and intelligent.
What I don't understand is how a music-manga can be successful. It surely can: "Beck", "Nana", "Nodame Cantabile" are all great anime, and they wouldn't get an anime adaptation without being a popular manga first. I will really have to try to read one such manga. I am not really into music, and I don't stick with any particular genres or band/performers, and I can't discuss the musical side of the anime, but I found music fine and catchy. There is a lot references and influence by real-life rock bands and famous performers.
My favorite part of anime was the stop-and-go romance between Koyuki and Maho, Ryussuke's younger sisters. I am glad that anime didn't put too much focus on it and left it on us to imagine the result. Best part of anime for me was at the end when Koyuki enters the stage alone. This is a typical shounen ending - a miracle. But that is the reason why we watch shounen anime... After that, the last two episodes almost ruined this anime for me with degrading resolution, and I started wishing it ended immediately after festival, but the actual ending wrapped things very fine.
From visual side, "Beck" is not very inspiring. Especially after watching "Nekomonogatari", animation and colors are pretty drab. Characters mostly look ugly, even when they should be good-looking. On the other side, there is a lot of attention put to details, like clothes, posters, instruments... As I said, music is very good, and so was voice-acting.
I am very glad that I finally watched "Beck" and would recommend it to anybody who like real-life anime and don't require action in it (except in case they don't like music). Even though it is not perfect, "Beck" definitely deserves it high grades with its interesting story and great characters.