Hey everyone. My friend and I are starting to play gigs these days country music.
I play the harmonica he does guitar and vocals.
I would like to streamline our process. He always has to tell me what key he is playing before each song. Is there a better way to do this rather than him telling be the key before each song?
Thanks!
You could always go “high tech” and use pencil & paper to make a set list 
…
Ok Slim, Let me rephrase the question.
Here is a scenario:
I go to a to camp fire there are about 6 people "I have never met sitting around the fire playing acoustics. I show up with my harps. instead of asking each guy what key they are in. is there anyway i could detect what key they are in without asking them?
There are apps for that…key finder is one…
OK, that is a different situation than you originally described:
where my suggestion would work quite well, provided you and your partner agree ahead of time on a set of songs that you will be playing.
For the new situation of showing up where strangers are jamming, then the suggestion by @johnreffitt1962 can work – but it is (in my experience) at least as fast to simply have a couple of harps in the “usual” keys (viz. C, A, G and maybe F or Bb), then quickly and quietly test each with the root, 3rd, flat 3rd and 5th tones for playing in 2nd position on each. Unless you are “tone deaf” you should be able to quickly notice which harp “fits” for the song being played.
You can also do this for other positions (e.g. 3rd, 4th, 5th, etc). Usually you find the required harp before testing them all and can jump in and jam with the others. If not, then simply “sit out” that song because you perhaps do not have the needed harp or cannot play one of the harps in a position that is appropriate for the song.
These are ways that I have done this over many years (starting back when there were no “smart” phones for dumb people). Try these out and see how well you fare.
Just ask. If you were in a club with 5-6 musicians at a jam you’d expect the key would be announced for each song.
If there are multiple guitars at the campfire they may “get it” by watching chords being played. Even for them it makes more sense to call out keys than hope to see in the dark by firelight. And trying to find the right harp in the dark and by testing it when the song has already started is ridiculous.
Don’t be embarrassed to ask. Others will appreciate it.
Never be afraid to ask. I haven’t played in a group before, but maybe if your friend would like to write out the setlist on a Google Doc or sheet of paper with the song keys next to each song, then you can figure out which key you would play in. Also hey there, I’m also a country music fan too. Have you ever heard about Terry McMillan.