Some of the musicians are credited at the end of this recording video which has "Mario Kart 8", "Dolphin Shoals" and "Moo Moo Meadows":
http://www.nicovideo.jp/watch/sm23447507
Electric Guitar: Takashi Masuzaki
Bass: Teppei Kawasaki
Drums: Satoshi Bandoh
Acoustic Guitar: Tetsuro Toyama
Trumpet 1: Eric Miyashiro
Trumpet 2: Koji Nishimura
Trumpet 3: Sho Okumura
Trombone 1: Yoichi Murata
Trombone 2: Kanade Shishiuchi
Alto Saxophone: Kazuki Katsuta
Alto Saxophone: Masato Honma
Tenor Saxophone: Masakuni Takeno
Baritone Saxophone: Takuo Yamamoto
Violin: Hitoshi Konno
Also lol at Kotaku not getting the gender of the person they interviewed correct.