カバー曲[kabaakyoku] remake of another artist's song (a "cover")
サイン曲線[sainkyokusen] sinusoid
愛唱曲[aishoukyoku] favourite song
委曲[ikyoku] details
一曲[ikkyoku] tune (melody, piece of music)

迂曲[ukyoku] meander
円曲[enkyoku] roundabout way (of speaking or working)
円錐曲線[ensuikyokusen] conic curve
円舞曲[enbukyoku] waltz (composition)
演曲[enkyoku] musical program

論う[agetsurau] to discuss
ファジィ理論[fajiiriron] fuzzy theory
意味論[imiron] semantics
異論[iron] different opinion
一元論[ichigenron] monism

一神論[isshinron] monotheism
一般論[ippanron] prevailing view
運命論[unmeiron] fatalism
概論[gairon] introduction
各論[kakuron] item-by-item discussion