MyMp3.com (Note: Servicemark of MP3.com)
HotMp3.com (UltSearch regged)
TopMp3.com (Oingo landing page)
--would all be better in my opinion than "TheMp3.com".
For most of the folks here, the name reads like the standard attempts one would take to still "get" a good name who's main .COM has been reserved.
[--NAME--]s, the[--NAME--], my[--NAME--], web[--NAME--], net[--NAME--], [--NAME--]site, etc, etc.
For Mp3.com the "the" doesn't make sense for me either.
TheMp3.com is worth less in the opinion of the folks here, because it is from the point of view of a reseller.
Like any domain name, you may be able to hype it right, and suck somebody into a purchase, but I have little doubt that a successfully branded website will NEVER be located there.
Even pronouncing it verbally will send almost all users going to MP3.com (spoken in what sounds like bad grammar). I cannot therefore give any appraisal value for it.
The only thing that would change my opinion is if there is significant TRAFFIC that may come to it. Traffic is always valuable, and if for some reason people come to this domain in droves, that may carry some worth.
~ Nexus