A recent discussion over at the Trumpet Herald forum got me thinking a bit more about the relationship between the pitch and dynamic being played by a brass player and how the breathing functions. Many brass players and teachers talk about using “faster air” for high notes, “blow harder” for loud notes, or “hot, wet, breath” for getting a rich, dark sound. These sorts of descriptions are fairly common, although many variations exist and not everyone feels similarly about their effectiveness in playing and teaching.
It is, of course, necessary to consider that playing sensations are a pretty unreliable way of talking about what exactly is happening in the player’s physiology or in the acoustics of the instrument. What to one player might feel like “blowing harder” might seem more like “faster air.” Furthermore, what works for a brass student and one stage of his or her development may become counterproductive later. This is why it’s important to have a good teacher who can watch you play and make corrections as needed. Teasing out those corrections often will take the form of analogies such as the ones I described, but we have to fall back on trial and error.
All that said, I find the science behind playing mechanics and instrument acoustics fascinating. Regardless of how you feel like you play, there may be some insights we can glean as players and teachers into breathing by taking the time to learn more. This can be a controversial topic, as reading through the Trumpet Herald topic can show. It’s even been a topic I’ve blogged about here that inspired some heated debate in the comments. In part this is due to differences in opinion about whether knowing this can be helpful or is a waste of time. My thought here is that trying to learn more about the way things work is never a waste of time, provided you are aware of the risks of going down the wrong path for a bit and recognize that you might just need to backtrack. Better still is to learn from those who have already done the research and had something to say about it.
One group of researchers, Jonathan Kruger, James McClean, and Mark Kruger, replicated a famous informal experiment that Arnold Jacobs supposedly did measuring the air pressure of brass players on different instruments and comparing how much blowing pressure and airflow were used for pitches. Jacobs noted that as the blowing pressure increased as the player ascended in range while the airflow decreased. He also claimed that players of different instruments would use a similar intra-oral pressure for the same pitch, so that a trombonist playing a “high Bb” would be blowing with about the same amount of pressure as a trumpet player playing the “middle C” (both pitches would be Bb4). Kruger, et al, found some of this to be true, but some of it to be different.
Intra-oral compression does increase as pitch increases and airflow decreases as pitch increases in each of the four members of the brass family. Both measures are also sensi- tive to changes in loudness (dynamic). Figure 2 shows changes in airflow and internal air pressure for a trumpet performer ascending the open pitches from the G below middle C upward while playing as close as possible to 85 decibels. As Jacobs observed, the larger bore instruments require less intra-oral compression and produce more air- flow when playing in their normal ranges than the higher instruments. Contrary to Jacob’s assertion about the simi- larity of instruments playing the same pitch, we observed measurable differences.
Other researchers have done similar experiments and found similar results. Kenneth Berger’s article in the Journal of Applied Physiology, Respiratory and articulatory factors in wind instrument performance (full article behind a paywall, abstract only), notes that the trumpet requires more intraoral pressure that other wind instruments studied.
A third paper published by 10éme Congres Fancaise d’Acoustique is thankfully written in English here. Freour, Causse, and Cosette noted similar results. In their article, Simultaneous Measurement of Pressure, Flow and Sound during Trumpet Playing, they wrote, “…it appears that pressure increases with both pitch and loudness, that flow increases with pitch and tends to decrease with dynamic.” They also note that the results of their study open up new questions that can now be addressed, such as the influence of air compressibility and even blood distribution in the respiratory system while playing.
So what are the implications for teaching and practicing brass instruments? At the very least I think we understand that blowing pressure and air volume do depend on the pitch range and dynamic being played. Knowing this, we might want to practice and teach being more aware of how we’re blowing while playing and changing those factors. Through this awareness we can learn our personal playing sensations in such a way as to memorize the feeling of when things are sounding and feeling good as well as better troubleshoot for those times when they are not.