An ixi-style read of the jam window, 6:00 to 10:30, tracked player by player. This is the rare jam led from the low end. Trey opens out front, but Mike's activity climbs until the bass overtakes the guitar and drives the middle of the jam, then walks the root from C up to G. Every claim traces to a per-stem chroma and spectral-flux pass across the demucs lanes. The staves are transcribed off the guitar and bass stems with librosa pyin, Trey above Mike. Mike's B♭ on the bluesy turn and his C-D-F-G walk to the dominant on the ride-out are read straight from the audio.
Sigma Oasis (jam peak, 6:00 to 10:30) — Phish · 2025-04-20 Moda Center, Portland
C major · Trey out front (6:00 to 7:07) · a clean C triad, the guitar leading
Trey leads the open, his guitar the busiest voice, stating G, C, E, the C major triad with the fifth and third up top. Mike anchors the floor on C, steady and supportive. Page comps the triad on piano, C, E, G, his organ a thin pad underneath. Fishman holds a mid-energy groove. A plain, bright C major to start, the guitar setting the color while the rhythm section holds the room. This is the only stretch where the jam behaves the way most do, with Trey clearly out front.
favorite momentThe clean C major triad at the open, Trey on the G and E up top over Mike's steady C, the calm before the bass starts to climb.
Mike steps up · the bass gets busy (7:07 to 8:15) · the major 7th brightens, the low end stirs
The balance shifts. Mike's activity nearly doubles, the bass suddenly busy under the held C, climbing toward Trey's level. Trey stays out front with a B entering his line, the major seventh brightening the C major. Page holds his comp, the keys steady. Fishman stays with the groove. The jam is still in C, the change here is not harmonic but who is moving, the bass stirring awake and starting to push from the bottom while the guitar adds the major-7th sheen.
Mike takes the wheel · the bass leads (8:15 to 9:22) · the flat 7th turns it bluesy, Fishman lifts
The turn of the jam, and it is unusual. Mike's activity overtakes Trey's, the bass now the busiest harmonic voice in the window, driving the jam from the low end while the guitar follows. Trey answers with a B♭, the flat seventh, souring the bright major into a bluesy C. Fishman picks up too, the drums at their densest here, locking with Mike's push. Page tracks the move. This is the rare Phish moment where the bass, not the guitar, is steering the harmony and the energy at once.
favorite momentMike's playing overtaking Trey's right here, the bass seizing the lead and driving the jam from the bottom, the flat 7th turning the room bluesy as Fishman locks in behind him.
Mike walks to G · the ride-out (9:22 to 10:30) · the root moves to the fifth, the jam tilts to the dominant
Mike finishes what he started, walking the bass root from C up to G, the floor moving to the fifth and tilting the whole jam toward the dominant. Trey follows him to G, his line on G, D, C, the guitar reacting to the bass rather than leading it. Page moves with them, the keys on G and D. Fishman rides the groove out. The jam that started as a clean Trey-led C major ends as a Mike-led move to G, the bass having taken the wheel and steered the harmony somewhere new before the ride-out.
favorite momentMike walking the root up to G at the close while Trey follows him there, the bass finishing as the player who moved the jam, the guitar in the reacting seat for once.
Sigma Oasis's stems carry bass, guitar, piano, other, and drums, no separated vocals lane, which does not affect a jam reading. Lead attribution comes from a per-stem spectral-flux pass: Trey leads sections one and two, Mike overtakes him in section three. The jam window was set by hand to 6:00, the developed instrumental stretch, since with no vocals lane the automatic vocal-gated picker landed on the earlier composed section. Key C major at 0.875 correlation.