Similar to other tests, with random tick speed at 500. I have a redstone clock constantly making several note blocks emit sounds near them(with other blocks below them altering the sounds they put out), they haven't grown since I planted them many minutes ago.

they do grow, they only mostly need noteblocks that emit percussions (bass drums/snare drums). sand or stone under noteblocks should produce percussion sounds.

truthfully, improving the music plant crop here: #6 has been on my list for so long. it's a concept that I'd like to be easier and more intuitive to work with, while not having to mash noteblock sounds together that ends up not sounding like music at all.