Many fiddlers don't. Many fiddlers and players of other melody instruments have no interest or even awareness of chords. When I first started as a hammered dulcimer player in 1980 I was one of those musicians. I will use my own experience to illustrate why I now think learning about chords is enormously helpful for melody players.
Fortunately for me, although I never took formal lessons on the dulcimer, someone else moved to the area shortly after I started playing who was a couple years ahead of me with the dulcimer.
Discovering the Importance of Chords. One day I was watching him play I noticed that sometimes when he played an A for the melody with his left hand, he would play an E on the bass strings with his left hand. But other times he would play a D or even an F# on the bass strings with the same A melody note. I had a sense that this was something important so I asked. His answer was that it had to do with the chords that went with the melody. If an A melody note goes with an A chord, an E would complement it. But if it goes with a D chord, a D or an F# fits but an E would sound out of place.
At this point I realized that chords were destined to be part of my life and it was time to learn some music theory. I got a couple books, but they all used the piano keyboard for their examples. Keyboards were expensive and mostly not all that impressive, so I didn't even consider them. I drew a picture of a keyboard and used that. It worked well for a while, but its silence was rather frustrating. My parents had an upright piano they weren't using, so I had it moved up to New Hampshire. It was great for learning about chords, and I discovered it was fun to play. It's now probably my strongest instrument.
They Even Help You Learn the Melody. Learning about chords was a major revelation to me. They turned out to be very useful for learning and playing melody as well as for playing harmony notes and even entire harmony lines. For example, consider the tune Bay of Fundy, played frequently at contradances. Here is the notation for the B part.
Important Note: If you click on a note the tune will start playing from where you click. Click outside the tune to stop playback.
If you look at it, the first measure has the note sequence A, D, F# and A twice. These are the notes of a D chord. The second measure has the notes G, B and D — the notes of a G chord. The third measure is the same as the first, as are the fifth and seventh measures; and the sixth is the same as the second. So nearly the entire B part is chord based, with a couple connecting runs.
Once you learn to listen for chord patterns it becomes easy to pick out those sorts of melodic patterns. So without even trying hard, knowing about chords makes it possible to figure out six out of eight measures. The eighth measure is pretty standard, so that leaves only one measure left to figure out.
Pretty useful to know about!
Effects on the Sound of the Tune. Furthermore, the choice of chords to play can have a profound effect on how a tune sounds to us. Below I've written out the A part of Bay of Fundy. For reasons that will make sense shortly I wrote out the two repetitions separately. You might notice that in the third measure there's a C natural instead of the usual C# of the key of D. In looking for the right chord, one possibility would be the C chord. But there usually aren't C chords in the key of D. On the other hand we expect there to be A chords. Perhaps it's an A-minor chord, which contains a C.
Well, try clicking on the music. It should play the melody with a simple accompaniment. I think most people will agree that the C cord makes for a good strong dramtic effect. On the other hand, playing an Am just sounds a bit odd.
On the Next Page: Are there correct chord choicesfor each tune?