Backstreet Boys is featured twice in the countdown: Backstreet Boys: I Want It That Way (1999) and Backstreet Boys: Larger Than Life (1999).
Despite to be a Top set in 1999, it features some 1998 songs: ATB: 9 PM (Till I Come) (1998), Barenaked Ladies: One Week (1998), Britney Spears: ...Baby One More Time (1998), Goo Goo Dolls: Iris (1998), New Radicals: You Get What You Give (1998), Shania Twain: That Don't Impress Me Much (1998), Sixpence None the Richer: Kiss Me (B&W Version) (1998) and The Offspring: Pretty Fly (for a White Guy) (1998). They were included despite to be released in that year because they reached the top chart in 1998 and also in 1999, or they don't reached the top chart in 1998 but in 1999.
Whitney Houston is featured twice in the countdown: Whitney Houston: It's Not Right But It's Okay (1999) and Whitney Houston: My Love Is Your Love (1999).
Jennifer Lopez is featured twice in the countdown: Jennifer Lopez: If You Had My Love (1999) and Jennifer Lopez: Waiting for Tonight (1999).
Shania Twain is featured twice in the countdown: Shania Twain: That Don't Impress Me Much (1998) and Shania Twain: Man! I Feel Like a Woman (1999).