This is a Tune Filled icon. We've made it in iOS style, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 13,000 icons, all in the same style and quality.
This logo is three horizontal lines spaced evenly from each other. On each of the lines is a small rounded rectangle, taller than it is wide. The top and bottom rectangles are a third of the way from the left, and the middle rectangle is spaced a third of the way from the right.