Twitter for Band Directors

Music Based Accounts
Band Director @BDTalkShop
NAfME @NAfME
Brian Balmages @BrianBalmages
Smart Music @SmartMusic

General Idea Accounts
Edutopia @edutopia
Jennifer Gonzalez @cultofpedagogy
TED Ed @TED_ED
NEA @NEAToday
Edmodo @edmodo

Here's a list of educators developed by Joseph M. Pisano:
https://mustech.net/projects/musictwitter/