Pitch Perfect adds 16 instruments, one for every Note Block type:

• Banjo
• Bass Drum
• Bass
• Bit Player
• Chimes
• Cow Bell
• Didgeridoo
• Electric Piano
• Flute
• Glockenspiel
• Guitar
• Harp
• Snare Drum
• Drum Sticks
• Vibraphone
• Xylophone

Right clicking will play a note, the pitch of which is dependent on the angle you're looking; if you're looking straight up, the note will be the highest pitch. If you're looking straight down, it will be the lowest pitch.

Credit to TheTrueDurgerKing for the textures!