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

褶曲[shuukyoku] bend
褶襞[shuuheki] folds (e.g. on a mountain)

活褶曲[katsushuukyoku] active fold
押しかぶせ褶曲[oshikabuseshuukyoku] overthrust fold