The great thing about blu-ray audio discs is, they don't need a menu at all. All you need are: -
A bunch of 'lossless' audio streams, such as: Atmos, Dolby True-HD, DTS-HD MA, 2ch up-to 8ch LPCM. Or 'lossy' audio streams such as: DTS, Dolby Digital, Dolby Digital Plus (all around the same duration).
A black encoded H.264 video stream (the same duration as the longest audio stream). But this could be a different video stream for each track.
A chapter navigation file.
After muxing the above together you get a perfectly playable 'audio only' BRD-A disc. It's even possible to burn the afore-mentioned onto single or dual layer DVD~R media as an AVCHD disc, if your player supports them