Worship that begins with a call to celebration, such as that in many of the psalms, follows a well-established biblical procedure for summoning the assembly into the presence of the Lord and encouraging its praise of the great King.
In ancient cultures, most people had no timepieces, and even the sundials and water clocks available to some were not very precise. Thus, a community could assemble together for worship only when summoned by a signal or other announcement, as in Muslim cultures today. In Israel, the ram’s horn and the silver trumpet were used to call the people to festal assembly (Lev. 23:24; Num. 29:1); musical instruments, in general, were sounded to call the community together (Ps. 81:2–3; cf. the use of instruments to call the people to the worship of Nebuchadnezzar’s image, Dan. 3:10).
In the Psalms, the invitation to worship is frequently verbalized, often including the mention of music. Psalm 150 consists almost entirely of imperatives to praise the Lord with instruments and dance. Psalm 148 is devoted to an invitation addressed to all members of the created order to praise the Lord. Psalm 149 invites the people of God to rejoice in their King:
Praise the Lord,
Sing to the Lord a new song,
His praise in the assembly of the saints.
Let Israel rejoice in their Maker;
Let the people of Zion be glad in their King.
Let them praise his name with dancing
And make music to him with tambourine
And harp. (Ps. 149:1–3)
Many psalms begin with the invitation to praise the Lord. Worshipers are urged to “sing to the Lord a new song” (Pss. 96; 98); to “sing the glory of his name” (Ps. 66:2). Psalm 29 begins with the invitation to “ascribe to the Lord the glory due his name; worship the Lord in the splendor of his holiness” (Ps. 29:1–2; cf. Ps. 96:7–9). Several psalms begin by urging worshipers to “shout joyfully” to the Lord (Pss. 47; 66; 88; 100) or to clap the hands (Ps. 47), while the invitation to give thanks, or “make confession” of Yahweh’s redemptive acts, forms the opening of another group (Pss. 105; 106; 107; 118; 136). Other psalms begin with the summons to “bless the Lord” (Ps. 134 nasb) or to “bless his name” (Ps. 96:2 NASB); sometimes the worshiper calls on himself to “bless the Lord” (Pss. 103–104 NASB). The general imperative “praise Yah!” (Halllu Yah!) stands at the head of Psalms 106; 111–113; 117; 135; and 146–150.