Thanks for confirming. I also haven't found a working CD emulator for 95a (or OSR2), so much for cd audio capability. I've started to look at the ATAPI documentation.
Edit: In a real Win95 system, I believe cd audio is enabled by connecting a cable between the cdrom drive and the sound card. If this is the case, then the problem of redbook audio is not just about reading the disk, but then sending the data to the virtual soundblaster card. A solution could be devised that is similar to regular DOSBox + SDL_sound? The later Windows versions may not have had this requirement to playback redbook audio; however, the most recent versions apparently(?) do not support it at all.
It would be ideal to install an older version of daemon tools (v3.17 or earlier, perhaps 2.60), but the MSI installer does not work with 95a/b - these versions should be tried with 98se. If the file and registry settings could be extracted from the msi file, then perhaps it could be installed in 95a/b, too; given it uses a virtual scsi device and is compatible with 95. The older versions may not require the usb supplement and have a hope of working with cd audio. Another option is to emulate a partial or full USB device which may allow these cd emulators to fully function, but this is also given that this is the cause of the redbook audio not playing.
A last imperfect solution, given the mp3 (compressed audio) is laggy in 95/DOSBox, is to write the cd audio to uncompressed audio files (wav) and play those back in the 95 guest OS. It would be interesting to verify that the lag is caused by the playback of compressed audio, especially in the MM6 case (even though the patch only supports mp3, wav files could be played external to the program; further, that patch could be modified to accept wav files instead of mp3, but the patch is in Delphi and this may be a low reward solution).