While this verse is part of a list, commentators use the context to explain the nature of this musical service. Matthew Henry clarifies that the musicians' role was to 'prophesy,' which in this context means to praise God with great earnestness and devout affection under the influence of the Holy Spirit. This serves as a powerful reminder that true worship is not merely a formal exercise but a Spirit-filled activity. Without the Spirit's involvement, even the most organized service can become a 'lifeless, worthless form.'