C Standard Guitar
Two full steps down from standard. Used in doom metal and stoner rock.
C Standard drops every string two full steps below E Standard. The tone is deep, thick and heavy without the lopsided feel of drop tunings. Doom metal bands, stoner rock groups and some progressive metal acts use C Standard because it distributes the low pitch evenly across all six strings.
Your chord shapes and scale patterns are identical to E Standard, just four frets lower. A C power chord at the open position sounds massive.
C Standard Setup and Sound
Heavier strings are essential. A .012 to .056 set or heavier keeps the tension reasonable. The tone needs to stay tight on the low end, so modern high-gain amps with good note definition work better than vintage-voiced amps that can get muddy.
If you enjoy D Standard but want to go lower while keeping even string tension, C Standard is the next logical step. See also Drop C for a hybrid approach.