Difference between harp sheet music and piano sheet music?

Answer 1

(I am assuming a modern pedal harp rather than, say, Celtic harp.)

At a glance, a page of music for harp looks very similar to a page of music for piano, and it is generally possible to play harp music on piano without too much trouble, though it does not work the other way around.

Both are written on a Grand Staff, in concert pitch (not transposing), and the ranges are approximately the same (though the piano has a few more notes at the extremes). Harp music and piano music may include single notes or chords. Groups of notes doubled at the octave or at the sixth are common in both.

One important difference is the texture. Music for piano generally has more notes happening at any given moment. Full, thick chords are very playable and effective on piano, but they can be awkward on harp. Simpler, thinner textures and even single-note lines are very effective on harp.

If you play one instrument or the other, or if you are interested in writing for one or the other--or if you just have lots of intellectual curiosity--the following details may also interest you.

The instrument construction results in one difference that is highly technical but also very important. The piano has one key for each note (C, C#, D, D#, E, F, F#, etc.) but the harp only has one string for each letter (C, D, E, F, etc.). The seven pedals of the harp are used to change the accidental associated with each letter. Each pedal operates all the strings one letter, and it has a position for flat, sharp, and natural.

It would be easy enough to play F, F#, G, G#, A in double-octaves on the piano. To play the same thing on harp, you might set the E pedal to E-sharp and use that to play the F. Likewise, you could pre-set the F pedal for the F#, and the G in the natural position would be OK. You might even pre-set the A pedal as A-flat to play the G-sharp, but then you would have to adjust that pedal quickly to get the A-natural. And this is a simple example of the problem!

As a result, it is possible to write combinations of notes for piano that are simply unplayable on harp. Notes for the harp are also written according to this system of practical necessity rather than the rules of Music Theory; a major triad on D might be written D-Gb-A, which will look strange to the pianist's eye.

There are performance markings that are peculiar to each instrument. Sheet music for harp often has markings to alert the harpist when it is necessary to change the pedals. You might see "Bb Eb" printed with letters below the bass staff. Alternatively, if many pedal changes are needed, harpists scribble a tiny diagram of the pedals in their scores, and some composers use this system.

Piano pedal markings, on the other hand, tell the pianist to use the damper pedal to sustain the sound, among other things. This would not help a harpist. Harp music normally sustains all the time, and so there is instead a marking in harp music to tell the harpist when to stop the strings from sustaining!

Performance markings also indicate techniques that may not transfer from one instrument to another. Harpists touch the strings to get bell-like harmonics and other sounds from the harp. Even when similar effects may be possible on piano by reaching inside and touching the strings, most pianists would not know how to do them.

There are many other subtle differences, but one comes to mind that could have obvious consequences. The glissandois a very idiomatic gesture on the harp, and composers ask for it frequently. A glissando can also be performed on piano, but the resulting sound is so different that it seems like a completely different thing. The problem is that the piano's glissando is always on either the white keys or the black keys or, less often, all of them. The harpist, owing to the instrument design described above, can set the pedals to the notes of a four- or five-note chord (typically a seventh chord or dominant ninth chord) and play it as a glissando. Consider the pedal setting B, Cb, D#, Eb, F#, Gb, A. Each of the flat notes sounds the same as the note preceding it, so the resulting sound is B, D#, F#, A with lots of doubling that produces a rich shimmering sound. The richness of sound is also characteristic of the four- or five-note chord itself, common in the Romantic era in western Classical Music, rather than the more common triad.

Since the harp's glissando is so often used in this way, a piano may actually seem more harp-like when it plays a fast broken chord--and that's why we call a fast broken chord an arpeggio. It sounds like the harp (Italian arpa).