夷俗[izoku] customs of the barbarians
雅俗[gazoku] refined and vulgar
還俗[genzoku] return to secular life
旧俗[kyuuzoku] old customs
古俗[kozoku] old custom

州俗[shuuzoku] local customs
淳風美俗[junpuubizoku] good morals and manners
世俗[sezoku] common customs
世俗化[sezokuka] secularization
世俗主義[sezokushugi] secularism

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