I have come across lyrics and chord sheets that show "Base key : (A, B, C etc)". What does it mean?
Passion Planetshakers, Legacy Base key: A Intro Fm Ab/C Db Fm Ab/C Db Ab Verse Fm Eb Ab This passion deep within my soul
I expect you're looking at this page: https://www.psalmnote.com/song/passion-chords-planetshakers
The page has a transposition feature. With 'A' selected at the top of the page, the song is shown in F minor/Ab major. Press 'A#', it goes up a semitone into F# minor/A major. And so on, for the other possible selections. You can also use the Transpose Higher/Lower buttons. Press them and see what happens.
The choice of 'A' as the 'base key' seems arbritary, unconnected with the actual key of the song. They might just as well have labelled the buttons '+1', '+2' etc.
Here's a song on the same site where, with 'C' as 'base key', the song actually IS in C, and therefore the 'base key' switch makes more sense.
Just a case of sloppy website design, I think.
Usually refers to the key the guitar is tuned to. Standard guitar tuning is A (hence base A). But it can be tuned to any key - as far as I’m aware. D is a very common key to tune a guitar to in rock music.