Oh my heart is a sad love-song from the first half of the sixteenth century. It's attributed to Henry VIII. It's for three people - soprano, alto/tenor, bass.
The custom in Southron Gaard is to sing the song this way:
- Soprano line only
- Soprano line and alto/tenor line together (no basses)
- All three parts, normal volume
- All three parts, loud
- All three parts, soft
There are a number of recordings online. You might have to add "Henry VIII" (or similar) to a search to weed out the modern stuff. I rather like this choir. For a very different sound: this version for countertenor and lute.
Computer-generated sound files (midis), to help in learning parts.
The song plays twice through.
There is sheet music in the Big Lochac Snogbook (pdf) (page 50).