Why do trombone players move the slide...
November 1, 2014 2:05 AM   Subscribe

when they don't seem to be changing the note proportionally?

I'm a idiot [clearly] about these things but it seems there are large movements with the slide that I see that don't translate into what I hear.
posted by vapidave to Media & Arts (15 answers total) 7 users marked this as a favorite
Best answer: Trombone players can reach several notes with each slide position by changing their aperture (the position and tightness or looseness of their lips.) If you were to take a piece of pipe or garden hose and practice buzzing (blowing a raspberry, basically) into it, you'd find you can do that too. The combination of multiple notes in each position and the ability to change the tube's length by sliding into other positions gives the trombone player the ability to play scales and songs etc.
posted by cellura p at 2:30 AM on November 1, 2014 [4 favorites]

Best answer: To add to cellura, all brass instruments have tones that the player can control simply by changing the player's mouth. This is why a bugler can play all those notes with out having any moving parts at all.

But the bugle has "gaps" in the notes it can play. It works out for western music that just seven positions on the trombone (or seven fingerlings on trumpets or tubas, etc) can fill in all the gaps.
posted by "friend" of a TSA Agent at 2:38 AM on November 1, 2014 [4 favorites]

Best answer: There's also this.
posted by moonmilk at 3:20 AM on November 1, 2014

Best answer: To get a little bit more technical:

Brass instruments create a column of moving air that resonates at certain frequencies, so that when the player buzzes into the instrument with their lips those frequencies are amplified. Which frequencies are amplified? This is actually really simple, it's the frequencies that have wavelengths that evenly divide the length of the column of air. So if a trombone has about 8 feet of tubing, then it amplifies tones with wavelengths of 8 feet, 4 feet, 2 feet, 1 foot, 6 inches etc.

If you want to change the tones coming out of the instrument you can do one of two things (or more often both). The first is you can change the length of the column of air, which will change the wavelengths/frequencies that are amplified, but this by itself gives you very little tonal range. In order to to jump a single octave, you would need to double or halve the amount of tubing that you're using, which just isn't feasible, especially if you want an instrument with a range of several octaves.

The other thing you can do is tighten your lips to change the frequency of the buzzing, and thus change which wavelength of the resonant wavelengths dominates the sound. This gives you a much wider range (from the lowest possible up as high as your lips are able to take you) but especially at the lower end, it has big gaps in tone. (Taps and other bugle calls are classic examples of melodies you can play on just a single tube length, but you'll notice that they all have big jumps in tone at the bottom end.

The combination of these two results in a system where small movements in pitch are governed by the slide, and large movements may or may not require movement of the slide, depending on the exact placement of the starting and ending notes, for example a chromatic scale (one which uses every note used in traditional western music) starting at the C below middle C would look like this (where the positions run from 1, where the slide is all the way in, to 7, where the slide is all the way out):

C - 6th position
C# - 5th position
D - 4th position
Eb - 3rd position
E - 2nd (or 7th) position
F - 1st (or 6th) position
F# - 5th position
G - 4th position
Ab - 3rd position
A - 2nd position
Bb - 1st position
B - 4th position
C- 3rd position
posted by firechicago at 5:03 AM on November 1, 2014 [5 favorites]

Best answer: Now here's a non-technical version, or my "mental map" as a former trombone player:

Imagine that when you are playing the trombone, there are "floors" of tones stacked like a building. In firechicago's list above you see that the main floor is the one that runs from F in first position with the slide all the way in, down to B in the 7th position with the slide all the way out. (He doesn't list the B, it would actually appear on his list at the very beginning, right above the C in 6th position)

Mentally, I picture the notes in exactly the opposite of how he wrote them. When you are moving the slide out, you are walking down the slope of the floor in a chromatic scale.

The floor that starts on F is kind of the wheelhouse of the trombone, it is the easiest floor to be on and the most natural to happen when you buzz your lips into the mouthpiece.

To jump to a higher floor, you squeeze your lips tighter. To drop to a lower floor, you loosen your lips.

As you jump higher, the floors get closer and closer together. They also get narrower, with a steeper slope that makes the seven slide positions move closer together. Lead trombone players spend a lot of time on those higher floors. As you ascend the levels it takes less and less slide movement to hit the desired pitches, and the floors are so close together that you never really need to get out past fourth position because you can just jump up to the next floor to hit that pitch. Notice on firechicago's list how E can be played at both 2nd or 7th position and F can be played at both 1st and 6th position. That is the same exact note, not an octave jump -- it should literally sound identical either way you play it. In my mental map you are either standing on the top of the slope of one level, or on the bottom of the slope of the level above.

So when you are watching a lead trombonist playing a solo, because they want the sound to carry and be melodic (and frankly because playing the higher pitches is more "flashy"), they spend most of their time on those higher levels where it takes much smaller slide movements (but much more precise lip tightness).

Conversely, as you go lower the floors do get spaced further apart. If you drop to the level below the Bb in firechicago's list, there actually start to be some unreachable notes because the gaps between the floors become too wide and the slope is too gentle such that the slide cannot reach far enough to hit the missing notes. That is why some trombones have an extra coil of pipes in the loop that sits on the trombonist's shoulder. There is a thumb trigger (or sometimes two) that opens up those pipes and adds them to the overall length of the slide. This makes those missing notes accessible again. It also gives the player another way to avoid having to make extreme slide movements. Without the attachment, you might have a piece where you need to quickly go from 1st position to 6th position (Bb to C) which is an extremely wide move, and prone to being off pitch. With the attachment, you just play the first note and then press the thumb switch to play the second note without having to move your slide. It is faster and easier to keep in tune, and again reduces the slide movement.

At least, that's how my brain was wired to perceive what I was doing as I played. Your mileage may vary.
posted by Lokheed at 5:48 AM on November 1, 2014 [35 favorites]

A piece of trivia: When Bach was alive, the "trumpet" he wrote for was actually a bugle. It didn't have any valves. One of the Brandenburg Concertos features a trumpet in the last movement, and to modern ears it is played very high. That's because he needed to get it up high enough so that the trumpet player could hit all the notes using lip alone.
posted by Chocolate Pickle at 7:38 AM on November 1, 2014

Best answer: Former tuba player here.

The only notes available to the player when the slide or valves on a brass instrument are in any given position form a harmonic series.

You can fake just about any high-pitched note by sticking with high-numbered harmonics, whose pitches are all relatively close together, and bend them into tune by altering the size of your mouth cavity. But if you want to play arbitrary notes at lower pitches, you need to alter the instrument's tube length so you get access to the harmonic series based on different fundamental pitches.

And there are plenty of cases where the easiest way to jump up by a semitone, in the lower pitch ranges, is to go from a harmonic of something quite low to a different harmonic of something quite high, or perhaps the other way around; so even though the final pitch coming out of the instrument isn't very different, the tube length (which is what sets the fundamental frequency) has to be.

Here's a recent MeFi post about a woman who can do this with just her head - no trombone required.
posted by flabdablet at 11:07 AM on November 1, 2014 [1 favorite]

Trombone players can reach several notes with each slide position by changing their aperture (the position and tightness or looseness of their lips.)

The term for this is embochure.
posted by ludwig_van at 11:51 AM on November 1, 2014 [1 favorite]

Response by poster: Thanks all. I am learning, thanks for teaching. I owe you all a snack.
And a follow up if I may. Umm, a trombone player might move the slide far in order to be able to more easily reach the next note which might not be immediately availabe to their embouchure? i.e. they move the slide in anticipation?
posted by vapidave at 7:12 PM on November 1, 2014

Can't really do it in anticipation, because that would change the note that's playing at the time. Making the intended note come out of your trombone involves simultaneously having the slide in the right position, holding your mouth right, and breathing right.

For any given note there will be a variety of slide positions that let the instrument resonate at the required pitch; for example, the fifth harmonic for a tube of length L is the same frequency as the sixth harmonic for a tube of length 6L/5 or the seventh for length 7L/5 and so on.

However, the note that comes out of a brass instrument is not a pure tone at the frequency of that note: it also includes other harmonics based on the actual tube length. The ear doesn't usually perceive these as separate tones, but as contributions to the timbre of the note being played. The conventional slide positions are those that make the resulting notes sound more like a trombone than a moist high pitched fart.
posted by flabdablet at 11:13 PM on November 1, 2014

Right, you would never move the slide in anticipation while actively blowing through the horn. You can't move the slide without bending the pitch.

True, you can also achieve some pitch-bending by mouth and air support alone (non-trombone brass instruments do it all the time), but the amount of bending ability gotten that way is not nearly enough to offset slide movement.

Of course, the entire point of a trombone is all the pitch bending. No other instrument gives you that kind of freedom for scoops, falls, and extreme vibrato. It's a fun instrument to play, particularly for jazz.
posted by Lokheed at 4:29 AM on November 2, 2014 [1 favorite]

a trombone player might move the slide far in order to be able to more easily reach the next note which might not be immediately availabe to their embouchure?

Given sufficient grit and determination, any note is always available to the embouchure. But it sounds a lot better if you can persuade the instrument not to fight about it.
posted by flabdablet at 5:53 AM on November 2, 2014 [1 favorite]

I think you're asking about the nervous tic some wind instrument players engage in - wiggling the slide, flitting the valves on brass instruments, or running the keys on a woodwind while not actually playing. It's kinda like jogging at a stop light - just something to do to keep the mind and body in sync while they don't necessarily have to be in sync.

(I did it all the time on my clarinet and sax.)
posted by notsnot at 7:02 AM on November 3, 2014

Trumpet player for three decades.
When I was in high school, I bought a craptacular trombone from a flea market. After fooling around with it, I found all 7 positions and they mapped exactly to the 7 prescribed valve combinations on a trumpet:
ooo oxo xoo xxo xox oxx xxx
From there on out, to play trombone, I read it as trumpet music. 2nd valve goes here (a few inches out), 1st valve further out, etc. and then correct by ear.

There is a bit of a lie in trumpet though: every valve combination is a concession and is made to be in/out of tune to whatever degree the manufacturer decided. I use my 1st and 3rd slides all the flipping time to actually play in tune, whereas a trombone player adjusts with the slide as a matter of course.
posted by plinth at 1:06 PM on November 3, 2014 [1 favorite]

There is a bit of a lie in trumpet though: every valve combination is a concession and is made to be in/out of tune to whatever degree the manufacturer decided.

That's kind of inherent in the arithmetic of the standard valve arrangement, unfortunately. All a valve can ever physically do is add a length of tube. For a valve to cause a consistent pitch interval regardless of the settings of the others would require it to multiply the present tube length (including any extra added by other valves) by a fixed amount.

In fact this probably could be achieved given a complicated enough arrangement of valves, but in practice it's dealt with by incorporating tuning slides - essentially, tiny versions of a trombone slide - into the extra loops switched in and out by the valves.

Here's a really good article on the physics of brass instruments for those interested.
posted by flabdablet at 8:16 PM on November 3, 2014 [2 favorites]

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