Wow the songbird trap looks amazing! Good job S8.
For fangbeasts, if you just chop musical ferns you should get enough beasts to spawn to finish the event. Fangbeasts also spawn from farmhouses and cows, so you should definitely get enough if you're just hitting all the places you'd go anyway for the event. Just make sure you have no monster on your board; it's super useful to play with the music on since you'd know right away if there's a monster somewhere.