Here’s part of my quest to get more people to learn tunes by ear.
Chords will help you find the melody
First, here are the three chords you need for most old-time tunes in D, shown with two positions each. When you know these chords, you can quickly find the melody notes for just about any D tune you’re likely to hear at a jam.
Here’s a PDF chord chart for those chords, including a fretboard map showing the notes you’re most likely to use.
Use the chord shapes to learn a new tune
Once you know the chord positions, use them to learn “Toads in the Woodpile,” an original yet reassuringly formulaic D tune.

This was fantastic and super helpful. Thank you for taking the time to make this easier for us all.
Holy cow, that was fun! Thank you so much.