If you are using Apple computer (macOS) and have your music in Apple music app (formerly iTunes), either imported local or Apple music streaming service, you can download the Apple Remote App on your iPhone or iPad and then control your Mac Music App library through this Remote App. I use it this way to navigate my Mac music library and it works fine. My Mac computer is connected to a DAC via usb cable.
Also, if you have a newer iPad with usb-c and the latest iPadOS, you do not need the camera connection kit cable. You can directly connect via usb-c. I also use this way by connecting iPad to my DAC and stream music from Apple music App and Spotify. In this case, I have not yet been able to figure out how to connect my iPhone Remote App to my iPad Music to navigate library.