Shir means song or singing. It appears about 90 times. It refers to songs of praise, victory songs, love songs, and prophetic songs. The 'Song of Songs' and many Psalm titles use this word.
Song is the language of worship, joy, and testimony. Israel sang at the Red Sea (Exodus 15). The redeemed will sing a 'new song' (Psalm 96:1). Heaven resounds with songs of praise (Revelation 5:9). Music is not incidental but integral to worship — joyful response to God's mighty acts.