Grojband is a very cleverly-written and finely-executed show. For a show that revolves around music, this show definitely doesn't disappoint with the different song styles done each episode. Whether it's traditional rock, or something different like polka, banjo, romantic ballad, gospel, and even light elevator music, the show branches out to appeal to every music fan.
The characters are very likable and easy to relate to, whether it's to one's self or to one's bossy older sister who always needs to have their way.
The plot lines, however, is what sells it for me. Rather than pattering to the children and having a bunch of poo and pee jokes, the characters actually have to brainstorm and overcome what could easily be real-life scenarios kids and teenagers could face. Sure, the quick fix isn't as easy as fixing in the show with a diary meltdown, but it still offers some believable problems a human being could face, such as crushes, jealousy, personal change, and of course, sibling rivalry.
As for the show's humor, it has a fairly-balanced mixture of pop culture and original jokes to keep the viewer entertained. It's not littered with non-stop jokes about Pop Musicians and Social Networking, just enough to move the story along or to make a quick chuckle. The show's original humor, though, is neatly-timed and keeps both children and teenagers alike amused, especially with the Looney Tune-esque sound and visual effects.
In conclusion, in a era where cartoons have to be taken seriously to get one's approval (looking at you, Legend of Korra), Grojband is a nice chance of pace. It has an even balance of real-life situations to an extent you don't get bored with it, as well as plenty of well-timed cartoon gags and jokes. Give it a watch!