If you’re wanting to use MacBook Pro Touch Bar with Logic Pro X, you’ll have to wait for an update coming by "early next year.” It’s the macOS software for professional songwriting, editing, and mixing.
In response to an email, Apple marketing director, Xander Soren told an AppleInsider reader that “we are fully committed to Logic Pro X, and we will be bringing Touch Bar support to Logic by early next year.”
The software is available at the Mac App Store. For new users the software costs $199.99. It requires macOS 10.9 or later.