There are at least three bands or artists that go by the name of Amanda:

1. AmAndA is a theatrical rock band from Belgium. Queen meets french rock meets heavier tone.

The band's reputation is growing and on May 2nd 2007 they played a sold out venue with a full symphonic orchestra.
The new album "La Maison De Flore" is getting impressive reviews in webzine and AMANDA is starting to get airplay even on some mainstream radios.

Members are:

Thibaut de Halleux: lead vocals
Xavier Rossey: guitars
Saaam: guitars, vocals, accordeon
Claude : bass
Mik3: keyboards, vocals
Greg: drums

AmAndA have two albums released: "Qui est Amanda ?" (2002) and "La Maison de Flore" (2007).

2. "Sånggruppen Amanda" is a Swedish group of singers and players that performs their music togenther with dancing and acting. When they use instruments, they are often classical or african in origin. They sing a broad variety of styles, from Mozart's Lacrimosa to Swedish Folk Songs, Voodoo child by Jimi Hendrix and various african songs.
See http://www.amanda.nu for more info, and sound samples.

Amanda has about 30-40 members. (A listing here would be a little too verbose. See their home page for a list.)

Amanda has released Three CDs with music from their shows: "Amanda", "AmandAndra" (Swedish for "AmandTheSecondOne"), and "Tres".

3. Amanda Louisa Kretz Lameche, known professionally as Amanda, is a pop artist born in France. She was also the first young pop act to sign with Madonna’s Maverick Records. In 2000, she had recorded her first album entitled Everybody Doesn’t. "Everybody Doesn't" was also her first and only single to date, peaking at #81 on the Billboard Hot 100. There was a second single to be released, but because of weak album sales, Maverick dropped Amanda.