めざせポケモンマスター / Aim to Be a Pokémon Master
Composed by: Hirokazu Tanaka
Arranged by: Cheryl (Chell) Watanabe
Performed by: Rica Matsumoto
Lyrics by: Akihito Toda
Info:
here and
here
ポケットにファンタジー / Fantasy in My Pocket
Composed by: Hirokazu Tanaka
Arranged by: Nobuyuki Nakamura
Performed by: Sachi (Sachiko Kobayashi) and Juri (Juri Inata)
Lyrics by: Akihito Toda
Info:
here
Shinji Miyazaki both composed and arranged music for the first series (and continues to, actually, AFAIK).