I heard James Leva say, at Galax, that he started playing more C tunes when he learned how fun it was to play them in second position. I tried it and he's right. If you're saying "What's second position?" here's your answer.
Guitar players are taught, early, that fingers correspond to frets: first finger, first fret; second finger, second fret, and so on. By the time you run out of fingers, on the fifth fret, you're ready to go to the next string anyway. (For most strings, the fifth fret is the same as the next string, open.)
It's just a rule of thumb, since when you play chords you may need to stick more than one finger on the second fret, but it's a useful place to start from.
Mandolins are tuned in fifths, not fourths, so if you play a scale, you don't get to move to the next string for notes until you get to the seventh fret. I've seen hands with a thumb and five fingers, but not a thumb and six. What to do, what to do?
The neck's teeny, compared to a guitar, and the frets are close together, so each finger can be responsible for two frets: first finger, first and second frets; ...; fourth finger, seventh and eighth frets.
Playing a scale doesn't mean you need to play every fret on every string. If you try scales in the common keys -- D, G, A -- you'll see that each finger only ever plays one of those two frets, though which fret may differ from scale to scale.
Better still, since you can move to the next string up once you pass the sixth fret you never actually need to use your pinky, which is your weakest anyway.
That's first position.
Now shift your left hand rightwards, up the neck, until your first finger is where the second one used to be. Your index finger is covering the third and fourth frets, your middle finger, the fifth and sixth, and your third finger, the seventh and eighth. That's second position.
You can see where it goes after that. Move your index finger to where your ring finger would be in first position, and you're in third position. Move it to where your pinky would be, fourth position, and so on.
Try playing a couple of C tunes in second position, and you'll see what James Leva means. Texas Gals is a widely played C tune, but if you're looking for lots more, go out and get a collection of Mississippi tunes and you'll find a bunch. I like Captain George Has Your Money Come? just for the title.
As you'll discover, being in second position for these tunes only really helps you for the top two strings, A & E, so you'll wind up more comfortable moving your hand out of first position and back again, too.
Altamont, The Last Shot Got Him, That's My Rabbit (My Dog Caught it), Knoxville Rag, ... loads of good C tunes.
