Amazon, Walmart and Microsoft have stuff all to do with digital music. Heck, Microsoft's most recent contribution is shutting down their DRM servers from the retired MSN Music store resulting in no more moving your music around ever. A company like that not being able to get a look in is not a sign of monopoly, just incompetence.
The other problem is that no other companies who might stand a chance are really trying - if a huge techno-music company such as Sony-BMG made a proper attack, such as "our entire catalog, open, for $X/year" and that went nowhere, then I'd start to be convinced.
The other problem is that no other companies who might stand a chance are really trying - if a huge techno-music company such as Sony-BMG made a proper attack, such as "our entire catalog, open, for $X/year" and that went nowhere, then I'd start to be convinced.