Easton's Bible Dictionary (1897)
Virgins, a musical term (1 Chr. 15:20), denoting that the psalm which bears this inscription (Ps. 46) was to be sung by soprano or female voices.
Smith's Bible Dictionary (1863)
(virgins), (Psalms 46:1) title; (1 Chronicles 15:20) Some interpret it to mean a musical instrument, and others a melody.