https://canta-per-me.net/yuki-kajiura/interviews/rocketbaby-english/ said:
Studio Gear: PowerMac G4/533MHz (384M) and many instruments
Sound Tools: ProTools, Digital Performer
RB: What is your process for creating music? In what kind of environment do you create your music?
YK: Mainly I write tunes in my room with piano, but if I hit on a melody when I’m walking, I write it as a score. Though there are many ways to create music, I value the first phrase that comes into my mind
(usually it is a melody, sometimes a rhythm or like a riff of synthesizer), and regard the arrangement
as a decoration which emphasizes the phrase I want to express. I make arrangement in the way as above, maybe a matter of course.