Friday, August 5, 2011

Happy Birthday Norman Pickering!

My mentor Norman Pickering turned 95 last month! To do his life justice would require several long books but here are some highlights. An early hand injury playing baseball ended his aspirations as a professional violinist, and he switched to the French Horn. After receiving his engineering degree, he graduated from Juilliard (he was a classmate of the late cellist Bernard Greenhouse), then played horn in the Indianapolis Symphony Orchestra in the late 1930s before joining the E.G. Conn company in 1940. There he did research into musical instruments and helped design many instruments, including a role in the design of the famous Conn 8D French Horn, used by most of the major United States Orchestras. He also taught at the famous Interlochen music camp. With the start of World War II, the E.G Conn factory was converted to making precision gyroscopes used in airplane navigation, sparking his interest in flying and aviation. He returned to the New York City area and was a regular substitute during the 1940s in the New York Philharmonic, the Metropolitan Opera and other orchestras. His dissatisfaction with the quality of audio reproduction led him to design the first lightweight, high fidelity phonograph pickup cartridge. Versions of the Pickering cartridge are still sold today. He was one of the founders of the Audio Engineering Society in 1948. He was conductor George Szell’s personal recording consultant for several years. He did research into violin acoustics and somehow found the time to make over 50 violins and violas. He was active in the Violin Society of America since its early days and served as President. One of his significant accomplishments was to popularize violin acoustics to violin makers. He also was a pioneer in using ultrasound to image the human eye.

D’Addario entered the violin string business with the purchase of the Kaplan String Company in 1981. They became aware of Norman’s research into strings and hired him in 1983. He designed all of D’Addario’s bowed strings until I started at D’Addario in 1999. The Helicore string line is one of his most well known accomplishments in string design. I owe my success at D’Addario and the violin acoustics world to Norman.

Although his arthritis limits his physical activities, Norman is still mentally as sharp as ever! Happy Birthday!

Friday, June 24, 2011

Violin Open E String Whistling Problem (Part 3)

Let us explore some common beliefs about whistling E-strings.

"The open E whistles easier if you play a D natural right before it." False. The D natural has no effect on the whistling; it just happens to be the most common note played before the open E.

"The open E whistles easier on a down bow." False. The E will whistle on an up bow just as well. It has so happens that crossing from the D to E string is most commonly done on a down bow.

"The bow hair needs more rosin, or needs to be rehaired." There is some truth to this. If the bow hair is in poor condition or lacks rosin, this will make it harder to start a normal note and make it easier to whistle. However, if your bow hair has enough rosin, adding more will not prevent whistling.

"Gold plated E strings are easier to whistle." There is some anectodal evidence to support this, but no proof. If true, it might be due to the smoothness of the gold plating, which reduces torsional damping due to the string rubbing against the bridge string notch and nut.

Certain types of plastic sleeves or string notch covering may make whistling easier. I recently encountered violins with bad whistling problems that had a very smooth and shiny bridge string notch covering material instead of the traditional parchment.

Any adjustments to violin setup that changes the response of the E-string can affect whistling. However, there is no single violin adjustment that will prevent whistling in all cases. Therefore, luthiers might go through a lengthy list of adjustments, including soundpost, bridge setup, changing the shape of string notches, the tailpiece assembly, etc. in hopes of finding a cure. The only remedy that will work all the time is to use a string like our Kaplan Solutions non-whistling E (KS311W 4/4M).

Wednesday, June 1, 2011

Violin Open E String Whistling Problem (Part 2)

When I designed the Kaplan Solutions non-whistling E-string (KS311W 4/4M), I spent hours trying to make an E string whistle so I could take some measurements. This after years of trying to achieve just the opposite!

Last summer at the VSA-Oberlin Acoustics Workshop, Aaron Boyd, concertmaster of the Tucson Symphony Orchestra, taught me a very reliable way to whistle an open E. Start the bow moving above the string first, then contact the E string. This works equally well down or up bow! I then remembered a talk by acoustics researcher Knut Guettler where he showed that quick and clean starts of (normal) bowed notes required just the right amount of bow acceleration. I finally realized why preventing an E string from whistling is so difficult.

The normal bowed string vibrates in a transverse (side-to-side) motion, producing a saw-tooth shaped waveform. This motion is called the Helmholtz motion after the great 18th century German physicist Hermann Helmholtz who discovered it. Only certain combinations of bowspeed, acceleration and pressure produces a stable Helmholtz motion.

When the bow contacts the string while it is already moving (such as crossing to the open E string from the A string), conditions are favorable for the start of torsional vibrations, and unfavorable for the start of normal transverse vibrations. One rarely whistles an open E-string when starting a note with the bow already on the string, or after changing bow directions, or when playing repeated notes because in these situations the bow starts each note with zero velocity, which favors the start of normal transverse vibrations over the torsional.

Therefore, the way to prevent the whistling E using bowing technique is to stop or slow the bow before it contacts the E-string. In addition, an increase in bow pressure on the E will favor the transverse motion over the torsional, and that is typically what players try to do. However, this usually fails because the increase bow pressure is often accompanied by an increase in bow speed, which is the exact opposite of what is needed! Unfortunately, the bowing conditions required to prevent the whistling may be undesirable musically.

In part 1, I discussed how wound E-strings can solve the whistling problem. In the next part, I will explore some common beliefs about whistling E-strings, and what might be done to minimize the problem through instrument setup.

Wednesday, May 25, 2011

Violin Open E String Whistling Problem (Part 1)

One of the most frustrating problems for violinists is the whistling E string. You play on the D string and when you cross over to the open E, it whistles with an annoying high frequency squeal. Or you play a chord in Bach and the open E string whistles.

This whistling is not due to poor bowing technique: I have heard the best violinists in the world whistle their open E-strings.

The whistling open E string is caused by the string vibrating in a torsional (twisting) motion rather than the normal Helmholtz (transverse or sideways) motion. The torsional vibration frequency for an unwound plain steel E-string is approximately 4,800 Hz (an open E is 660 Hz), and independent of the diameter of the string or the tuning. The torsional damping (damping is how quickly the vibrations die away) is extremely low, so once the string starts to vibrate torsionally, it does not want to stop very quickly. Your finger tip provides very high damping, and that is why the whistling does not occur with stopped notes. (Stopped notes can still squeak due to low string damping and poor bow technique, but that phenomena is generally not due to torsional behavior.)

The lower strings don’t have whistling problems because the windings provide extremely high torsional damping. That is why a wound E-string (for example our Helicore H311W) is more whistle resistant than plain E-strings. We also add a damping compound to our wound E-strings which increases torsional damping. For the ultimate whistle-proof E-string, try our Kaplan Solutions Non-Whistling E string (KS311W 4/4M). In addition to the winding and added damping compound, it uses a stranded steel core, which lowers the torsional frequency and further increases torsional damping.

The Kaplan Solutions Non-whistling E-string is also very sweet sounding compared to solid steel E-strings, yet has plenty of power due to its high playing tension, comparable to heavy tension solid steel E-strings. The string has a solid ball-end, which cannot be removed, so we include an adapter which allows it to be used with common hook type fine tuners.

In part 2, I will discuss why it is so difficult to prevent an E string from whistling.

Wednesday, May 4, 2011

Playing Harmonics

One of the most overlooked aspects of playing harmonics on bowed string instruments is the bowing point. A common cause of harmonics not sounding is that the bowing point is too far away from the bridge.

When playing higher notes, the bowing point usually has to move closer to the bridge, since the vibrating string length is shorter. (The same proportional bowing point to the bridge is closer to the bridge in absolute distance for a shorter vibrating string length.) We usually make this bowing adjustment automatically as our left hand moves up the fingerboard when playing really high notes.

When bowing harmonics, one must remember the bowing point needs to be based on the effective vibrating length of the harmonic and the actual sounded pitch, and not where the left hand actually stops the note. For example, the typical artificial harmonic is played in the low positions, but actually sounds two octaves higher, so it must be bowed as if you were playing the normally stopped note two octaves higher. (In this particular case, the string is actually vibrating in four short segments, like four links in a sausage.) This means the bowing point must be closer to the bridge.

Addendum: I should add that the bowing speed and force (pressure) should also be based on the effective vibrating length of the harmonic and the actual sounded pitch, and not where the left hand actually stops the note.

Tuesday, April 26, 2011

False Strings

I discuss false strings in the latest June 2011 issue of Strings Magazine. Here’s the beginning of the article:

"One of the most common questions about stringed-instrument strings is about the nature of false strings. What is a false string? Musicians often use the term to describe any string that does not sound right, such as a string that sounds dead or won’t bow properly. However, a false string technically occurs when a string doesn’t produce the correct pitch due to a lack of uniformity or defects. In rare cases, the instrument itself may be the source of intonation issues.

To understand false strings, it helps to understand a few basic concepts. When we talk about uniformity, what we mean is that the string is not what physicists call an “ideal string.” An ideal string is uniform in density and mass along its length and is completely flexible. This ideal guides the choices that string designers make with materials and varieties of string design.

False strings were more common when gut was the primary string material. Gut strings are a natural product made from highly processed sheep intestines…”

Fortunately, false brand new strings are extremely rare today. However, strings can become false with use. For more details, see the rest of my article "How to Know if False Strings are Hurting your Sound." A subscription to Strings Magazine is required to access the article.

Friday, April 8, 2011

Violinist Alexander Markov at Carnegie Hall

Last October, almost 30 years after his Carnegie Hall debut recital, violinist Alexander Markov returned to a sold out Carnegie Hall to perform his own “Rock Concerto”. He repeated a version of this concert in the Norwalk Concert Hall (Connecticut) last week to a much smaller, but no less enthusiastic audience. The Norwalk Concert Hall brought back fond memories since I grew up in neighboring Wilton and spent many Saturday mornings rehearsing with the Norwalk Youth Symphony in this hall.

Alex became interested in rock music during high school and it became a passion along with Paganini. He commissioned a custom 6-string violin (it is actually viola sized) to use in his rock band, but he was very frustrated with the guitar strings he was using which could not be bowed easily. I designed a special low F string for his instrument, which uses a magnetic pickup, and he was thrilled with the results!

Alex performed the Tchaikovsky Violin Concerto for the first half of his Carnegie Hall concert. It was an extremely satisfying “old-fashioned” performance, more concerned with emotional communication as expressed through Alex’s own unique tone and phrasing rather than the more “clean and correct” playing of most modern performances. For his Norwalk concert, he played a variety of show pieces. My favorite was his remarkable performance of the Paganini “Moses” Fantasy Variations played all on the G-string. It was also delightful to hear the Sarasate “Navarra” duet with his father Albert Markov, who is still in remarkable playing shape. And of course he played his signature Paganini 24th Caprice (watch on YouTube) with its famous left-hand pizzicato variation.

Alex has revised his Rock Concerto since the Carnegie concert. The Carnegie version was more dramatic and operatic, with a huge chorus, and long sections. The pacing of the Norwalk version was much improved, with shorter sections, and featured Alex more prominently. The most heartfelt moments were Alex’s lyrical solos, tinged with bitter sweetness. It must have been difficult for his family to emigrate from the Soviet Union in the 1970s. Did I hear echoes of this? The music is completely different, but it calls to mind the emotional landscape of the musical Fiddler on the Roof.