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

八尺瓊[yasakani] large jewel
八尺瓊の勾玉[yasakaninomagatama] large jewel
瓊矛[nuhoko] jeweled spear (jewelled)

天の瓊矛[amanonuhoko] Ama no Nuhoko
瓊瓊杵命[niniginomikoto] Ninigi no Mikoto (Japanese deity, grandson of Amaterasu)