Plant it to grow Sheet Music: Piano Note. If you aren't in range of a Boombox, this will play a piano note for you. Put it in different places for different pitches.
Sheet Music: Piano Note Seed price in Growtopia: sells for about 48/WL (median of 2 offers from community Discords, past 30 days). Live price chart and the latest buy and sell offers.
Recently sold at: POHHSSP