Sorry if I'm not supposed to reply to this thread, but I think I found something while messing around in VBA's Memory Viewer. I was trying to figure out how to make the Harp of Ages work so that you could choose which song to play, because when I gave it in-game, you weren't able to select the song. I figured out that the address C6B7 determines which song is currently selected by the harp, whereas how many songs you have, and whether or not you get a menu, is intertwined with the number of seeds address, C69E. Sorry if this has been posted before. I'm currently trying to work out a list, but for now I can say for sure that the values '61' to '7F' is where you first get two song options, Echoes and Currents and 'E1' to 'FF' gives you all 3 songs. Changing the 2nd number gives different seed combinations. There are some other values inbetween these (81-DF), but the harp song images don't match up with the tunes or the names, so I guess they're kinda buggy. It seems like the first number goes up by 6 (hex) and the 2nd goes up by 2 (hex), with the 2nd number always being an odd number.
I'm not super great with hex editing, so I could be wrong about some of this stuff. Maybe someone more experienced could also play around with this and see what they can find out. I'll still try to map out a full list for people to use.
Huh, really? That means the upper 3 bits of the seeds byte actually are used. Interesting find. What might help you understand the value is it's a bit mask - each bit is a boolean (true/false). There are 8 bits in a byte, so the first 5 bits are for the seeds and the upper 3 are for the harp songs (According to your findings anyway).