Oh, that part was pretty obvious to me and
anybody who has played OoT If you look around the village you'll soon enough see Sarias' name, so I just tried to play OoTs'Saria's Song (which skull kid was playing in the lost woods in OoT, down right left x2) in front of what seemed like a clean musical score on the wall in one of the upper level treehouses and voila
(also, the start menu tells Link knows two songs in the start, Sarias' and Eponas' songs, and even though you can't see the icons you can play them in the start menu, eponas song is identical to OoT as well)
Just realised, on the previous page I posted a screencap where I am playing Sarias Song in the correct place to progress using Wii64, with the icons visible
I mean, I've finished OoT (and MM and WW with their ocarina/windwaker songs as well) so often by now that I know pretty much all of the songs by heart