When I think “well known harp tunes” what comes to my mind is traditional Celtic tunes. O’Carolan tunes like Captain O’Kane and Carolan’s Welcome, oft-played favorites like Minstrel Boy, and OF COURSE, Greensleeves.
Or do you mean folk like Peter Paul & Mary? Most of those tunes have very simple chord arrangements.
If your left hand is truly lost and you need to work up an arrangement quickly (read: fake it for a pub audience!) try simply plucking the 1st and 5th notes of the chord (or reverse it, 5th and 1st) with your left hand on the beat, and concentrate on the melody with your right. If the melody is engaging, you’ll be surprised how little you can get away with on the left until it too gets up to speed.
For what it’s worth, here’s my approach, which is decidedly non-academic. (I do honestly apologize to the music teachers who may be reading this.)
As background, I’d played guitar for years so I’m familiar with common folk tune chord progressions (more on that below).
First, I worked through Sylvia Woods’ How To Play The Harp and Pam Bruener’s Play The Harp Beautifully books and DVDs, to get proper technique. Videos were a godsend.
Next, since I’d already been playing hammered dulcimer, I started playing some folk tunes I was already familiar with on dulcimer, on harp. Because both instruments are diatonic, the transfer was pretty easy for melody / right hand. Please Note: Rumor has it that Greensleeves is the single most often requested harp tune by audiences, so you can’t go wrong adding that one to your repertoire.
Then, I bought “fake books”, sometimes called “lead sheets”. They are melody and chords only, no left hand. Whenever I play from a harp book I essentially ignore the written accompaniment — my small hands usually can’t reach the hand span required anyway, so why suffer frustration and
One more quick note (har har!) about playing 1st-and-5ths, to make it easy:
Instead of playing 1st lower and 5th higher, reverse it. Play the 5th UNDER the 1st. Here’s how:
Let’s say you’re wanting a D chord (i.e., all the guitarists are playing D at this spot). Place your left thumb on the D. Gently and naturally lay your next fingers on the next lower strings. Your index finger (2 in harp-speak) will be touching the C, your next touching the B, and your ring finger (4 in harp-speak) will be touching the A. Now lightly lift fingers 2 & 3 off their strings. No need to tuck them under towards your palm; that’s wasted effort and can’t be done in a hurry. Now your thumb is on D and ring finger (4) is on A. Pluck them together (comfortably, sort of squeeze both fingertips toward your hand’s center-line).