Kate M
Jaco... first and foremost, thank you so much for the compliments! Steve and I are really glad you liked the song.
As far as the bass parts being played, Steve is taking care of those with his MIDI guitar. He usually programs the top 2 strings to trigger bass tones on his keyboard. The classical guitar training he has enables him to play interdepentant rhythms between his fingers and thumb with a finger style technique.