Symbol in Piano Music-->Looks like a harmonic mark, but in piano?

I have a piece of piano music that is marked with an open circle. It pretty much looks like there's an o above the note. This means natural harmonic in stringed music (I'm also a violinist) and I can't find any other meaning in any music dictionary or symbol list. But you can't really play harmonics on piano.

If anyone know why these would be in a piano part, let me know. If they are something else, please tell me. If they are harmonics, please tell me how you play harmonics on the piano. That doesn't make sense. Any ideas?

The marking in question is generally used as an indication to dampen a string with one finger while playing on the key. Sometimes a diamond shape is used to indicate the same thing (among other markings).

One form of keyboard harmonics can be achieved by depressing one key(silently) and then striking and rapidly releasing another key (at octave displacements) resulting in the sounding of the harmonics from the depressed key. Schoenberg used a diamond shaped note to indicate the key(s) to be silently depressed and then regular notes to show the ones to strike forcefully (usually with an accent and an sf marking).

Musician, composer, teacher.

I've never seen that used for anything other than brass or string instruments. So, like you, I have no idea why it would be in music written for piano.

I have played the piano professionally for many years, and I don't recall seeing a mark like that in piano music.

Hmmm. I'll star you and look it up and get back to you.

If the music you are looking at was written during the mid 20th century or later, then perhaps it actually is a harmonic. There have been numerous piano works that required the pianist to place a finger on the piano strings before striking the key (John Cage, for starters, but also some more traditional composers). I'm not certain if someone like Debussy didn't do it also, or at least try for a semi-muted effect using a quick hit with the sustanuto pedal.

I've never actually seen it in earlier piano works (before 20th century). But if it's 20th century or later music, it may actually be a piano harmonic. I took a special music programme in junior college, and we had to compose pieces for the piano using the full instrument - this means not only the keys, but also the wood, the strings themselves, the pedals, etc. The aim was to create special timbres from the traditional piano. A piece my teacher made us listen to had the player strumming the piano strings while holding down the respective keys with the other hand silently. What came out was a harp-like sound that's really beautiful. I did the same for my assignment, and I put in a couple of harmonics too. Basically for each harmonic note, you touch the strings inside the piano (you need a grand piano for this) at a specific point - usually the halfway mark - and you strike the respective key with your other hand. The sound should come out an octave higher if you 'cut' the strings at exactly the halfway spot. They're rather difficult to do, took me a few tries to get a nice sound. You may want to put a little sticker marker on the correct spot so you don't have to guess where it is everytime. If you ask me where I got this idea from, it's from the harp - because I play harp also, and I thought if you can 'cut' the harp string (using your hand as the tool) in half or quarters to produce specific harmonics, why not on the piano since it obviously has strings too?