And Miriam sang to them is literally “and Miriam answered to [or, for] them.” This suggests that Miriam may have “led them in the refrain” (Jerusalem Bible), or “took up from them the refrain” (New Jerusalem Bible). Good News Translation has “sang for them,” but this would not have been a solo, since the first word of the song is a command to sing. Sing to the LORD is therefore not the same as verse 1, for here the imperative form is used as an invitation, “You [plural] sing.” The rest of the verse, however, is identical with verse 1.

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .