Use the search bar with terms like date:[2000 TO 2009] combined with mediatype:audio to filter results strictly to that decade.
The Internet Archive (Archive.org) is a massive digital library that houses millions of free books, movies, software, and, most importantly for music lovers, a vast collection of audio recordings . Searching for "2000 songs archive.org" opens a portal to the "Y2K" era, featuring everything from chart-topping pop hits to the "wild west" of early internet indie demos. 2000 songs archive.org
You can find digital preservation of physical CD sets, such as Pepsi Chart Hits Vol.1 from 2000 , which features iconic tracks like "Livin' La Vida Loca" and "Mambo No. 5". Use the search bar with terms like date:[2000
For musicians, the Songs of the 2000s and Best Pop Songs: 2000-2009 collections provide scores and play-along tracks for hundreds of the decade's biggest hits. You can find digital preservation of physical CD