Enter now works like a modifier key: - Press + hold Enter: engages hold mode. Any note keys pressed while Enter is held auto-latch into heldKeys. Also immediately snapshots anything already playing so the existing chord sustains. - Release Enter: disengages. New notes stop latching, but the notes added while Enter was held stay sustained. - Press Enter again later to add more — as many times as you want. - Backspace: clear all holds. Audio cues: ascending pair on Enter-down (660/990Hz), descending pair on Enter-up (990/660Hz). Visual indicator shows "HOLD n" with a pulsing green tint while Enter is held, and "H:n" in red once latched. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>