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From Never Recycle:
Beginner Reading Music: Treble is an app that lets you practice reading sheet music on your phone. It is very simple to use and is perfect for when you have a few moments to kill and you want to learn how to read sheet music fluently. While teaching you to read the music it also plays the note back to you so that you can start to recognize the pitch of various notes in relation to the sheet music(you can play without sound just as fine too!). The app comes with three different modes so that you can challenge yourself as you progress. Each one increases your reading speed to better enhance your sight reading capabilities.