Is the ringing pitch usually different from the bowed pitch?

Edited: July 11, 2020, 8:41 PM · Yes, a plucked string, or a string left vibrating freely after the bow leaves it, will vibrate at a lower pitch than that same string when bowed. And a strongly bowed string will emit a higher pitch than that same string lightly bowed. I find the effect more pronounced with older strings that have lost some of their elasticity, which provides an alert that it might be time to replace them. This is why we bow lightly when tuning, and we don’t try to tune by plucking. Just one more degree of complexity for string players.

July 11, 2020, 7:52 AM · Mark, thanks for answering my question. I think I always noticed a difference in the sound, but the chromatic tuner quantified it.

July 11, 2020, 7:03 PM · I was curious about the OP question, so I tried it on my cello.

The ringing D is exactly the same pitch as the stopped/bowed D that stimulated the ringing pitch. (I used a Peterson strobe tuner to check.)

I wonder what other factors are in play resulting in the Mark's observations?

Edited: July 11, 2020, 8:42 PM · “.....the stopped/bowed D that stimulated the ringing pitch.”

It’s unclear what you’re talking about. If your talking about an open string vibrating sympathetically with another stopped bowed string (it seems like that), then you’ve completely missed the point of the op’s question and my response.

I slightly edited my first response to hopefully make things clearer.

July 12, 2020, 4:04 AM · The pressure of the bow stretches the string slightly, raising the pitch.

This can be offset by a frequent (and personal) tendency for tones to seem lower as they get louder.

July 12, 2020, 11:46 AM · Does it matter that I am playing wound gut strings?

July 12, 2020, 2:48 PM · I am not convinced that tuning, or perhaps checking tuning, by plucking is necessarily a bad thing, provided it is just sufficiently audible, not a performance pizzicato, and the player's ear is good enough to hear and assess the differences in pitch necessary for accurate tuning.

The energy transferred into the string by quiet plucking is insufficient to alter the tension of the string, and therefore its frequency, by other than an infinitesimal amount. Guitarists, harpists, and players of other plucked instruments perforce have to tune by plucking, and generally make a good job of it.

I tune (quietly!), and check my tuning, on occasion by plucking, as well as by bowing. I have even been known to quickly check the tuning in 5ths of the A and E using the harmonics, a dreadful cardinal sin according to a conductor we once had.

Edited: July 12, 2020, 3:22 PM · Guitarists and harpists, etc., tune by plucking, but they also play by plucking, so it’s an entirely appropriate way for them to tune. String players play with a bow, so bowing while tuning is the best way for them to tune. Plucking lightly won’t alter the tension of the string, but bowing will. That’s the whole point here.

Rather that trying to argue about the subtleties of this, I’d like to suggest that anyone interested just get a really accurate tuner like the Peterson iStroboSoft app and test it for themselves. It’s not very expensive, and it’s worth the slight cost. Then come back and argue about it if you still have any doubts.