Exibition ( Composer )

Composer
David Arnold

He has composed many other films
Independence day 1996
Tommrrow never dies 1997
Stargate 1994

(possibilites)
Roland may have chose Arnold to compose most of his music because he has composed music with him before in the film Independance day. So its possible Roland felt that Arnold could work with him again.

Jamiroquai
His song 'deeper underground' was part of the music video to premote this film.

P.Diddy
His song 'come with me' was also another film used in the soundtrack in the godzilla film.

Both of these artists were very popular in the 90's so using them to promote their film through a music video would have helped increase the large potential audience.