This is a jazz standard. It's almost common practice now for Bluegrass artists to learn some jazz tunes. It can greatly help with your understanding of the fret board and give you new ideas for improvisation. In this chord melody version, the actually melody note is in the highest voice note of each chord(the note on the small D string). Make sure to really bring that note out, and don't let the lower chord notes overwhelm it. This tune sounds great with a swing feel. You can engage that option in the playback menu.