I see a lot to piano tutorials (like Laura Palmer's Theme) that use roman numerals to indicate chord progression.
In Laura Palmer's Theme, it's:
i - I - III - iv - I - vi - IV - i
In the key of C this progression is:
Cm - C - E - Fm - C - Am - G - Cm
However, due to the different halfsteps on the piano, and that there's only half-step between E and F, D and C, this seems complicated to transpose to new keys.
So isn't 12 half-steps being used, eg:
1m - 1 - 5 - 6m - 1 - 10m - 6 - 1m
Or are these actually different things, and there's something I'm missing here?