This brings us to an aspect of Keller's view of his music that may surprise some. "When The Mask of Memory came out, I ran some ads in Option magazine. The first one ran down the whole side of the page, saying in boldface at the top, New Age Sucks. After all, was Tangerine Dream "New Age" music? Absolutely not. None of the artsts that inspired me were – they were thrown in the New Age bin at Tower Records at some point, but that's not what they were. You were supposed to be doing LSD while you listened to Tangerine Dream! I knew that an album of melodic, electronic music would be automatically tagged as New Age, so I was very adamant that, no, it's not New Age music. Call it 'ambient' or 'post-modern Impressionist'– it’s film music, only without the film."
Keller's second release, Intermezzo, expanded on the melodic side of his music by adding cello. Telling the story of a day spent hiking the beach at Big Sur while emotionally processing the recent death of a close friend, it again connected strongly with Stephen Hill of Hearts of Space, who devoted half a show to the album. Keller also picked up another important fan: "John Diliberto called me and said, 'This is the best album of the year,' and I said, 'It's only January.' He says, 'I don't care.'" Diliberto being the host of syndicated radio program Echoes led to not only more airplay for the album, but also a Living Room Concert on Echoes.
Pendulum, the last of Keller's heavily electronic albums, again featured cello, this time played by ECM icon David Darling, a connection set up by Hill. Pendulum is a rarity in the Keller discography for depicting scenes not from, as before, a personal story but rather an actual book: Umberto Eco's Foucault's Pendulum. "After Pendulum was done in 1998, I made a very clear, purposeful decision to stop making music that couldn't be performed. That was my biggest frustration with all of this music, especially Pendulum; it was so much the product of the studio that it wasn't really practical to perform – there are five tracks of cello there, so you'd have to hire a cello quintet to perform the David Darling piece in concert." So Keller formed a trio with cellist Tania Simoncelli and bassist Mark Fassett and changed his own focus to acoustic piano. The result was the 2002 album Across the Sky and a greater focus on concert performances, most notably at San Francisco's Morrison Planetarium, where Keller had become resident composer.
Fifteen years down the road, Across the Sky track "A Star in a Stoneboat" was chosen for use on So You Think You Can Dance, giving Keller's music its biggest mainstream audience exposure thus far. Wonder what they would think of some of the major influences on his music: Keller admits, "I did quite a lot of Ecstasy in the '90s while working on Intermezzo, and several mushroom trips while working on Pendulum and Across the Sky. I also attended Burning Man from 1996-1999, and raves in San Francisco – but for me, the drug experience was always deeply spiritual and transformative, and this filtered its way into my work rather significantly."