Hi, everybody. I'm actually new to TalkBass (my second post!), but not new to the bass. I played for seven years, but not very much for the past two. Recently, I have picked it up, again, so I find myself re-learning a lot of material, and I have a question in regards to scale/mode/chord theory. It's a simple question, really, but I'm confusing myself trying to figure it out. Is there any way to know, by looking at a song's chart, what mode the composition is based on? Naturally, you can plot out the chords in relation to the key, but I'm thinking about how to handle a situation where you're handed the chart to a song you've never heard of, and are expected to play it without taking a couple minutes to look it over and figure it out. I know a lot of jazz compositions are based on the Dorian mode, and a lot of blues compositions are based on the Mixolydian, but how can you quickly know if it is or it isn't? Do charts come with key signatures? Am I worried about nothing? I'm moderately confused.