Maybe K-ON! strongest point is not the story, but the music… With all the albums sold up to this date, 552,491 albums, about half a million are sold up to date since 5 months ago when the first two albums are sold… which is impressive compared to how many albums are sold in the time period for Suzumiya Haruhi in total (this should make the Haruhiists jealous)…

Here is the rough data of how much are sold:

Death Devil – Maddy Candy – 15464 total sales, #31 for the week
Don’t Say Lazy – 161163 total sales, #59 for the week
Cagayake Girls – 144909 total sales, #79 for the week
Hokago Tea Time – 100221 total sales, #37 for the week\

Fuwafuwa Jikan :  77804 total sales (current, was not in top 100)

Mio Character Single :  51897 total sales (current, was not in top 100)
Yui Character Single : 50196 total sales (current, was not in top 100)

Data is gathered from this thread and CDJapan.

The music is pretty much the strong point of the anime… Rarely, the ED doesn’t give that much attention, but Don’t say “lazy” became insanely popular after the first episode that many people like with Hare Hare Yukai started to imitate it or even try to play the piece. If you were to search on Youtube, you will find a good amount of people playing it or even MADs that have it.

Also, believe it or not, Cagayake! GIRLS is also popular as well… Although not as popular as the ED, it’s still pretty popular that some people plays it… In my opinion, both of them are just as good… I really don’t have much of the preference…

The next album is Fuwa Fuwa Time (Lit: Light and Fluffy Time) and there are two versions of it, the first with Hikasa Youko (Voice of Mio) and second with Toyasaki Aki (Voice of Yui). Fuwa Fuwa time pretty much brought out a lighter side of Mio, however, after hearing both of them, Yui’s version was a little bit better since her character suits her for that song alot more and in my opinion, on the same level as God Knows and Lost my music… Also in the Fuwa Fuwa Time album is Tsubasa wo Kudasai performed by all 4 voice actors of the K-ON! Club and sounds pretty good…

Next is the character image album… The only ones that I heard so far are Mio’s and Yui’s and most of the songs sound pretty good as well. The only song that didn’t fit well is “Hello Little Girl” in Mio’s Image Album, but still sound good… The favorite songs from both of these albums are Heart Goes Boom!! from Mio’s Image Album and Sunday Siesta and Guitar ni Kubittake from Yui’s album… They sound great… but I can’t give a final verdict on these since I haven’t heard the rest of the image albums (I expect that they will be good.)

Also, the recently released image album,Houkago Tea Time with the full versions of Watashi no Koi wa Hotch Kiss (lit. My Love is a Stapler) by Toyosaki Aki and also another song, Fude Pen ~Ballpoint Pen~ (lit. Calligraphy Pen ~Ballpoint Pen~) sung both by Yui’s and Mio’s voice actors… Also included is Yui’s version of Fuwa Fuwa Time as mentioned earlier. Both of these songs undoubtedly sounded great… but haven’t heard the live mix yet.

Overall, the K-ON! music is what make K-ON! what it is… Even if you think the story line might not be the strongest… you have to agree that the songs in K-ON! are pretty appealing… more so than Super Driver and Tomare! which is terrible or average sounding at best (Again, this opinion is not meant to offend Haruhiists. I have to agree that although Hirano Aya is a good voice actor, she isn’t a great singer, but some of Haruhi S1 songs are pretty good). The songs sound good that it ended up on the top ten on my Last.fm charts:

Note, Top 11 was added due to a duplicate.

Yes, I have to admit that I am also a big fan of I’ve Sound/Key Visual Arts stuff and also Lia… mainly because her songs sounded beautiful (Tori no Uta, Light colors and Toki wo Kizamu Uta).

Note: K-ON! soundtrack isn’t mentioned since it doesn’t really have anything that interesting and it will probably put me to sleep (more so than the Visual Novel BGM (like Kanon and others of sort), which is alot more exciting) and Kyoani isn’t great at making BGM.