vox angelica

from WordNet (r) 3.0 (2006)

vox angelica
    n 1: an organ stop producing a gentle tremolo effect [syn: {vox
         angelica}, {voix celeste}]

from The Collaborative International Dictionary of English v.0.48

Vox angelica \Vox` an*gel"i*ca\ [L. angelica angelic.] (Music)
   An organ stop of delicate stringlike quality, having for each
   finger key a pair of pipes, of which one is tuned slightly
   sharp to give a wavy effect to their joint tone.
   [Webster 1913 Suppl.]