A pull, is D. A push is #G

[jetz320]

The title may have told you my problem. when i play open D string, it makes a lower pitch than when i pull. its only when it is: v it is closer to a #7 than 1. is there anything i can do about it? i have a music exam this sat, and i dont want to sound off key. thank you.

[dsouthwood]

Maybe this is all in my imagination, but this is what I think I have noticed: When I don't have enough rosin on my bow I tend to press the bow hair harder against the string; when I put more rosin on the bow, I can get the string vibrating with a lighter touch, and I hear less of a differential between the push and pull notes. So my guess is, when I press the bow hair against the string harder, I pull and push the string more out of line, but with lighter pressure I'm letting the rosin grab the string just enough to vibrate it without moving the string back and forth.

I would be interested in hearing others' experience with this.

Dennis

[song]

Jetz try to retie the qianjing. maybe with more loops this time. more than 6 around the strings.

If you are bowing so hard to the extent that the pitch is affected, you probably are bowing too hard.

SW

[jetz320]

hmmm....... thanks for all the replies so far. more rosin, and less pressure. if that doesn't work then ill retie the qianjin. thanks everyone

[calden]

Jetz:

Sorry for hopping in late on this topic.

I was instructed by two different teachers that the push-pull pitch change is a result of improper technique. I got over my issue with it by warming up very slow and with great bow pressure, paying attention to the point in time at which the bow changes direction.

Another thing I've found - when things start to feel funky and I can't seem to get the right amount of rosin on the bow and get a good feel for the "bite" of each note, it usually means it's time for a new bow. These bows just don't last as long as violin bows, and it's not just the hair. The resiliency of the bamboo gives out and doesn't have the same amount of spring, or something - but there's a definite crispness with a new bow that's not just the hair.

Carlos

[paulv]

jetz320 said:

hmmm....... thanks for all the replies so far. more rosin, and less pressure. if that doesn't work then ill retie the qianjin. thanks everyone

Jetz,

Carlos's reply is accurate -- it is about proper technique. My teacher told me this way back on my 2^ND or 3^RD lesson.

Also, bow life lessens as a person plays more as Carlos mentioned.

Oh yeah, if you retie the qianjin, don't forget to make sure your index finger's large knuckle can pass by the stick/strings space -- don't know if this was covered in another thread -- I don't frequent the forum much these days.

Regards,
paul...

[calden]

Another thought about bow technique (which would affect the changing pitch syndrome, as well as other things):

Practice in front of a mirror. (If you need to, fix your hair and dress nicely!) This will tell you a great deal about arm movement, wrist movement, bowing angle, and how your bow hand moves when you change direction. I would be willing, in fact, to bet that you'll see some aspects of your bowing that you wouldn't believe were true. I was shocked the first time I saw a video of myself playing. "Geez! I CAN'T be lifting my hand that much on the push stroke!" But it was, alas, sadly true.

Carlos

[calden]

Another observation:

Today as I was practicing I tried to intentionally create a pitch difference and I stumbled on another technique issue. The more the bow moves in a line parallel with the axis of the barrel the less pitch change. The more the bow moves in a line perpendicular with the axis of the barrel the more pitch change.

So if one bows in a line such that you are very near the neck with the bow, that's pretty straight and decreases the pitch change issue. But if one bows like this,



bowing ACROSS the top instead of in-line with the barrel axis, then there is a higher probability of a pitch change.

(Of course, if one plays the erhu like the woman in the picture, there will be a lot of other problems besides mere pitch change. Give her credit for trying, though.)

Carlos

[jetz320]

thanks for everything. i'm going to try this tonight then. i don't think it could be a technique though. this is only on my solo erhu. my other erhu and zhonghu sound fine. i'll try the angle thing though. thanks

[paulv]

calden said:

Another observation:

.............................................. But if one bows like this,



bowing ACROSS the top instead of in-line with the barrel axis, then there is a higher probability of a pitch change.

(Of course, if one plays the erhu like the woman in the picture, there will be a lot of other problems besides mere pitch change. Give her credit for trying, though.)

Carlos

Hi Carlos,

That picture brought back memories -- I saw that over a year ago on eBay for an erhu sale -- haven't stopped laughing at it since!!

Regards,
paul...

[calden]

I don't know if she realizes how much entertainment she's provided over the last couple of years. But as I said, I give her lots of credit for trying. I'm sure that's what I looked like when I first sat down in Shanghai at the music shop and tried my first erhu in 2001. Well, except not as pretty. Or as thin. Or as young. And with a bigger nose. And glasses, and white hair, and a goofy smile. And being a totally different gender. Etc.

Carlos

Carlos

[tj]

jetz320 said:

The title may have told you my problem. when i play open D string, it makes a lower pitch than when i pull. its only when it is: v it is closer to a #7 than 1. is there anything i can do about it? i have a music exam this sat, and i dont want to sound off key. thank you.

I had experienced the same problem, but not as bad. The difference I got was about 25 cents lower. This has always happened with the inner string (no matter what you tune it to - C, C#, or D) in an open position only. Sometimes the difference can be reduced or eliminated when the bow was pushed more horizontally by lowering the right hand a bit.

Physics tells us that frequency is inversely related to string length when the string tension is fixed. So when D (293.66Hz) dropped 25 cents lower to 289.45Hz, the relative string length increase is 6mm or almost a quarter inch. Now where does this increase come from? The obvious place is the QianJin, incidentally 6mm is the common width of 6-round cotton-string wound QianJin. As Sung suggested, redo the QianJin tying should help. Carlos suggested playing technique and I agree with that also. Personally I found lowering the right hand when pushing helped too. The physics origin of the effect of "playing technique" on pitch lowering is not entirely clear to me. I suspect that it has something to do with the friction between bow hair and the string and the resulting resonance of it. Well anyway making the QianJin as an "effective stop" is the key to solve this problem.

[calden]

Another observation I had when thinking about, and trying to replicate, this problem:

When doing the PULL stroke, it's very natural to have a nice wrist curve angle from the forearm to the hand. The bow is pulled properly - that is, the energy comes from the lower forearm and the hand functions almost more as a device to hang on the bow, and is kind of acting passively.

However, when doing the PUSH stroke, it feels less of a natural movement for the wrist to curve back, and the tendency is thus to keep a straighter forearm-wrist-hand line. When held like this, the bowing energy comes more from the hand rather than from the lower forearm, and the bow digs into the string more, sort of dragging the string. This definitely causes the pitch to lower somewhat. I am able to intentionally replicate this.

I would advocate, if you're having these problems, trying different things to MAKE this happen, then one can find out what NOT to do.

By the way, we've all seen the excellent performance by Jetz on Youtube, and he stated that this is only happening with one of his three huqins. I'm not suggesting that he's doing anything wrong. It's just something about that instrument that responds differently to his playing. My comments are meant more for beginners having this issue.

Carlos

[dsouthwood]

tj said:

jetz320 said:

the relative string length increase is 6mm or almost a quarter inch. Now where does this increase come from? The obvious place is the QianJin, incidentally 6mm is the common width of 6-round cotton-string wound QianJin. A

Here's what I am visualizing: I wound my QianJin with six turns around the strings. When I am pulling the bow, the string is being pulled slightly away from the neck, and the greatest string pressure is against the lowest of the six QianJin loops. When I push the bow, the string is being pushed slightly toward the neck, and the greatest string pressure is against the highest of the QianJin loops. This would account for the 6mm difference in string length tj calculated. So would the solution be to use fewer loops in tying the QianJin? I also tied my QianJin by alternating loops around the neck with loops around the strings, thus increasing the distance between the top and bottom loops of the QianJin. Would skipping those in-between loops help? I would love to see comments on my hypothesis before I test it by retying the QianJin, if you all would be so kind.

Dennis

[song]

All this technical analysis is very confusing. But I guess the problem stems from the fact that the qianjing is a rather 'weak' way of holding the strings together because it is made up of strings.

This is a method you can try to give the qianjing a 'stronger' structure. Use UHU glue and put a drop or more on either side of the qianjing and wait for it to dry before playing. It keeps the structure of the qianjing and at the same time retains the soft properties of the string.

SW

[tj]

song said:

All this technical analysis is very confusing. But I guess the problem stems from the fact that the qianjing is a rather 'weak' way of holding the strings together because it is made up of strings.

For a business guy, it ought to be confusing ;D

Cotton, synthetic, or super glue treated QianJins are as strong as the tension from the steel Erhu strings. Tensil properties of the QianJin string play some role but the key role was played by how "good" the QianJin was tied. We have to pay attention to the loops (whether 6 or more) so they have even holding powers. If the bottom loops are particularly loose, we'll have a problem.

If the technical analysis was right. The best QianJin should be one that apply pressure from both left and right on the contact section. I sense a business opportunuty, SW .

[jetz320]

i retied my qianjin and took out the tuner ones i had above them. it's fine now. the pitch is perfect. thank you

[song]

Great!

[karmeleon]

jetz320 said:

i retied my qianjin and took out the tuner ones i had above them. it's fine now. the pitch is perfect. thank you

If all else fails, take everything out and re-try, eh? ;D That's what I do when I can't figure out what has suddenly gone wrong with the sound.

sam