I am playing bass for a church retreat. The guitar players will change keys by moving their capos. What is the easiest way for me to tell what the new key I should be playing in on the bass. I know the answer is learn music theory but looking for a quick way on the fly. Thank you
Don't try to spend (waste?) time watching them. get used to listening for what must be the I chord bar - often but not always the first- and find that note a.s.a.p. It's what I do at open mic nights, and once you have that, the key is apparent. Play a couple of random notes, and work towards the root. It may take a couple of weeks, but you'll get quicker and more accurate. In fact, when someone at an open mic tries to tell me what key (I'm often on bass), it's best to just nod, and try the aforementioned method. It's safer!
You don't even need to know the key. Just see on witch fret they place the capo, and play everything the same amount of frets to the right.
Is there a cord chart from which you are playing? If not then it's time to write out a chart of what you're playing on the bass.
For example, the chart (for guitar) has capo 1 and the chords are in 'G' (G, C, D). In this case your chord chart would be one step higher as that is what is actually being played - the I, IV & V chords would be Ab, Db and Eb so that is what you would play.
I think if you combine the answer from Tim about watching and listening with the answer from Jimmy about the relationship between the chords, I IV V etc you will be fine. I just started playing bass in a band where they use capos a lot and speak in French and don't often know what key they are in or use solfege to communicate, its in 're' mineur
I'm converting all my chord charts to just I IV V etc. then its just a matter of finding the I and off we go
Hope this helps I'm new to the forum and look forward to learning from all of you