Assassination Classroom, an anime that was adopted from a manga series, was created in 2015. The show spans over 2 seasons compromising of around 20 episodes each. It is classified as an action/comedy anime and is ranked around #400 in popularity on myanimelist.com. The studio that created it was Lerche, which had also produced Danganronpa and Radiant.
The Earth is threatened by a powerful creature who destroyed 70% of the Moon with its power, rendering into the shape of a crescent moon forever. The creature claims that within a year, Earth will also be destroyed by him, but he offers mankind a chance to avert this fate. In class 3-E at Kunugigaoka Junior High School, he starts working as a homeroom teacher where he teaches his students not only regular subjects, but the ways of assassination. An assassination classroom begins.
(Note: these are the Japanese voice actors)
The song of Assassination Classroom are possibly one of the most recognized in the anime world. From Question to Tabidachi no Uta, it is probably one of the most diverse and best sounding soundtracks you will ever listen too, anime lover or not. (32 tracks in total, not including OST's)
Soundtrack Link