And the priests stood arrayed in their garments, with musical instruments and trumpets, and the Levites, the sons of Asaph, with cymbals: For the priests arrayed in their garments, see the comments on 1 Esd 1.2. The trumpets were short, straight musical instruments made of silver with a high, bright tone and a range of 4 or 5 notes (see Num 10.1-10). They were played exclusively by priests (2 Chr 29.26). Musical instruments may be rendered “other musical instruments” (Good News Bible). The Levites, the sons of Asaph refers to the Levite clan of Asaph. Asaph was a contemporary of David who is credited with a number of psalms. Cymbals were pairs of metal disks held in the hands and played by clanging them together.

Here is an alternative model for verses 58b-59:

• While the workers were rebuilding the Lord’s Temple, 59 the priests stood nearby. They were dressed in their official [or, priestly] robes, and were making music with trumpets and other instruments. The Levites from the clan of Asaph were also there, playing the cymbals.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Esdras. (UBS Helps for Translators). Miami: UBS, 2019. For this and other handbooks for translators see here.