Almost undisputably, Cubic Player is the best sound and music player for DOS, supporting many file types, including .S3M, .IT, .WAV and .MP3, as well as CD audio. This awesome player also supports a multitude of sound cards, ranging from the PC Speaker, through the GUS & SB, through to writing the output to a WAV file on disk!
I first encountered Cubic Player about a year ago. It was version 1.6 of the player, and already it supported plug-ins for loading different types of modules, and pretty high-res VESA graphics. The first time I listened to it, I was so amazed by the sound quality that I said to myself, "Now THIS is a cool player!" It is compatible with Windows 95, too, but only when it's in the foreground, IE don't try Alt-Tab or you could freeze your system. But it's not designed to be Win95 compatible; it's a DOS player, for DOS. Anyhow, it had (still has, too!) very high sound quality, and supported a large number of module files. It did not yet play CD tracks or .MP3/.WAV files, but it could show you a spectrum analyser for any of the standard soundcard inputs.
Now, with version 2.0, the player has been extended significantly. CD audio has been around since v1.7, but what I'm most impressed with is that it plays MP3 files. Here is a short description of MP3 files for those who don't already know.
MPEG is a multimedia file compression standard, designed primarily by the Motion Picture Experts Group (MPEG is, in fact, an acronym for this). It uses what's known as "lossy compression" to achieve high compression ratios. Lossy compression means that some of the original sound/video quality is lost, to allow for a much higher compression ratio. JPEG, a still image compression format invented by the Joint Photographic Experts Group (again an acronym), also uses a lossy compression algorythm. However, usually the quality loss is so small that humans can't perceive the difference. This allows for amazing audio compression ratios of 12:1 and 16:1 for audio that sounds like it's still on the CD (that's about 850K per minute of CD-quality digital sound!). Video also achieves high levels of compression with very little quality reduction, especially using the algorythms involved with MPEG-3 compression, a proprietary format used on DVDs (Digital Versatile Disks) to compress the graphics. MPEG-3 actually often achieves mathematically lossless compression, which is a step above the previous MPEG formats. Unfortunately, as it is proprietary, we (the consumers) cannot make our own MPEG-3 files. But we do have MPEG-1 and MPEG-2 at our disposal, and this is quite enough for any non-professional purpose. An MP3 file is an MPEG-1 or MPEG-2 Audio Layer 3 compressed audio file. They allow an entire song, which in the WAV format might take 40 megs of hard drive space, to be compressed into about 3.5 megs, without any audible quality loss! It's really quite amazing!
Anyways, Cubic Player v2.0 supports this filetype, so I am quite impressed. You can download Cubic Player v2.0 right here.