The Hebrew word shir functions both as a verb meaning 'to sing' and as a noun meaning 'a song.' As a verb it describes the act of singing praise, especially to God. As a noun it denotes a musical composition — individual psalms, the Song of Songs (shir hashirim), and the 'new song' (shir chadash) of eschatological praise.
Song in the Hebrew Bible is the primary vehicle of covenant celebration and theological expression. The first recorded song in Scripture is Moses' Song of the Sea (Exodus 15:1 — 'I will sing to the LORD, for he is highly exalted'), and the Psalter is entirely built on shir. The imperative to sing a 'new song' appears six times (Psalms 33, 40, 96, 98, 144, 149; Isaiah 42) and anticipates the eschatological new creation. Revelation 5:9 shows the redeemed singing a new song before the Lamb — Christ's atoning work generates a song that transcends all previous praise. Paul commands believers to be 'filled with the Spirit, speaking to one another with psalms, hymns, and songs from the Spirit' (Ephesians 5:18–19). Singing is theological, communal, and Spirit-driven.