The singer wants it down a step; your voice wants it up two. Open Tune and the whole chart follows — every chord respells, the sheet re-lays itself, and the page turns stay where a page turn should be.
Tap the key up or down and every chord in the song moves with it — verses, bracket chords, intro rows, the changes in a bandleader chart, all of it. Nothing is a picture; nothing gets left behind in the old key.
A capo turns one song into several sets of shapes. The ladder in Tune lays out your options: the same song in the same sounding key, played as different grips.
Pick the rung your hands like. Charts that arrive with their own capo keep it — a chart written "capo 2" imports at capo 2, and back to original means back to that, not to zero.
Want the full theory? The free capo chart shows every shape at every fret, with a reverse lookup.
With a capo on, there are two true answers to "what chord is that?" — the shape your hands grab, and the pitch the room hears. The sheet shows written shapes by default (that's what you play from); flip to sounding when the bass player asks what key the song is actually in.
The Simplify switch strips every chord to its plain triad — the Cmaj7/E becomes a C, slash basses drop, the fancy extensions step aside. It's the campfire version, one toggle, and it's non-destructive: switch it off and every voicing comes back.