probably strengthened from psao (to rub or touch the surface, cf 5597); TDNT - 8:489,1225
AV - sing 3, sing psalms 1, make melody 1; 5
1) to pluck off, pull out
2) to cause to vibrate by touching, to twang
2a) to touch or strike the chord, to twang the strings of a musical instrument so that they gently vibrate
2b) to play on a stringed instrument, to play, the harp, etc.
2c) to sing to the music of the harp
2d) in the NT to sing a hymn, to celebrate the praises of God in song