End-to-end encryption and privacy controls.
Message and call for free* around the world.
Group conversations made simple.
Say it with stickers, voice, GIFs and more.
Reach your customers from anywhere.
[음악] 화음의 성질, 4성의 위치, 선율진행과 화성진행 (악보 및 듣기파일 첨부) http://yoonbumtae.com/?p=1691