From the raw data going back to withstand (level 83) through spurn (level 108) all have Song Window: 0 https://spells.eqresource.com/rawspells.php?id=55318 "Determines if a spell goes to the short duration window (song window) or normal buff window. A value of 0 indicates the spell will go to the normal buff window, any other value will send the spell to the song window." So while it is a short duration effect, it is set up to go to the main buff window.