Like with both seasons of Clannad, TBS seems to shaft the animation and only show it in 4:3 which make the animation rather disappointing … After Clannad went widescreen several weeks later, the results were awesome.
With K-ON!, it’s no exception… the animation improved tenfolds in Widescreen compared to 4:3. Comparison shots below:
I doubt the actual animation (keyframes) improved, but yes, it definitely + absolutely looks much better. The compositions of the scenes feel less scrunched up. The wonders of a little extra breathing room.