Trumpets and Trombones
So how many horns are typically in an orchestra? A small orchestra would typically have 2 French horns, large ones 4 to 6 or even 8. Some piece of music where the horns play for an extended period, the tune being played would be passed from one horn to another, while one horn player breathed and recovered, before chipping in again and taking over to give the other horn player rest. (Part-timers these horn players. You wouldn't catch a violinist taking a rest.) You'll notice that the number of horns are always even numbers and the reason for this is that compositions are written for horns in pairs, one horn taking the upper notes and the other horn taking the lower notes.
The classical example of writing for the French horn is in Till Eulenspiegel by Richard Strauss, with French horn section has the opening solo, beginning at the top of its range and descending wildly to his bottom notes. Clearly, Strauss, who was the son of horn player, knew what could be achieved. More often though, it's confined to smooth melodic passages and long sustained notes. The French horn can be vicious and wild though, as exemplified in the passages for 8 horns in Stravinsky's The Rite of Spring.
We move on to something that uses somewhat less tubing in its manufacture, the trumpet. William Shakespeare refers to the instrument as "the harsh resounding trumpets dreadful bray" (Richard II). This is not surprising as the trumpet, (along with the Scottish bagpipes) was used as a weapon of terror, to instil panic in the enemy (the walls of Jericho came tumbling down, and that was the fault of the acoustic weapon of a trumpet). Of course, here we are talking about bugle type instruments, the helpless trumpets of various types that were used for signalling, psychological warfare, religious ceremonies to scare the populous into belief and submission, and would I be right in thinking that a Maserati air horn is a kind of trumpet, this time signalling wealth and virility.
As I've indicated, trumpets have a long history, and trumpets were in common use by the time "Joshua arose early in the morning, and the priest took up the ark of the Lord. And 7 pre-sparing 7 trumpets of rams horns before the ark of the Lord went on continually, and blue with the trumpets; and the armed men went before them; but the rearward came after the ark of the Lord, the priest going on, and blowing with trumpets. On the 2nd day they compassed the city once, and returned into the camp: so they did 6 days. And it came to pass on the 7th day, that they rose early about the dawning of the day, and compassed the city after the same manner 7 times: only on that day they compassed the city 7 times. And it came to pass at the 7th time, when the priest blew with the trumpets, Joshua said to the people, shout; for the Lord has given you the city...... so the people shouted when the priest blew the trumpets; and it came to pass, when the people heard the sound of the trumpet, and the people shouted with a great shout, that the wall fell down flat." All this acoustic weaponry was in use in the 5th century BC, if we are to believe any of it. Certainly the trumpet in a simplistic form was in use by the Romans.
The cornet, so I've read, is a hybrid between the French horn family and the trumpet family, not quite sure why that said. Regrettably, because it's such a beautiful sounding instrument, it hardly ever used in the orchestral setting, though very well used in the brass band and the wind band settings. It's also been used by some of the great jazz trumpeters to get a soft and mellow tone in the jazz bands. Trumpets occasionally feature in barn dance bands, but this is more of a quirky thing to do to make the band a bit different from the marketing point of view, applies mainly to English barn dance bands, an attempt to liven things up, but I can't say I've come across them in other types of folk band.
Trumpets of old instruments, enabling the instrument to play the full range of notes for the same reasons that valving in a French horn achieves this. The most commonly used trumpet is the B flat trumpet with a range from F sharp below middle C to the B flat 2 octave is higher. There is the F trumpet, which plays higher and is often heard referred to by string players who perform the Bach Brandenburg concerto which includes the F trumpet, as the squeaky trumpet. There is also the so-called piccolo trumpet, which plays in D, and complacent very high notes, and at the other extreme the base trumpet, which is very rarely used and composed for. The high trumpet must been in common use in Bach's time, as he is written many virtuoso parts that are terrifyingly high, even for the best trumpeters, and in preference will use a specially designed instrument called the Bach trumpet, which generally has to be hired as it's such a rare instrument. In the modern symphony orchestra, 2 or 3 trumpets are normal, and in the piece like janacek's Taras Bulba, at least 15 trumpeters get lined up high at the back of the stage to blast the audience into awestruck submission and terror.
The trumpet is also a major jazz instrument, having the flexibility to sing like the human voice, inserting inflections, ornaments and subtlety that can be impossible to produce on most other instruments. I've talked about the jazz genre and trumpet playing elsewhere in my ramblings, so here I will come to a stop with its use in the symphony orchestra.
Now to the trombone, which doesn't use wells at all to change the length of pipe and the notes that it can play, but instead uses slide to change the length of tubing in a smooth and continuous, rather than discreet, way mean that notes can be slid up and down and the instrument can play in the cracks between the black and white notes of the piano, which makes it such a wonderful instrument for jazz, which lives and breathes in the cracks between the notes.
The trombone is the oldest perfected instrument in the orchestra. This doesn't mean that is the oldest of instruments, rather that it hasn't changed in form for a very long time, whereas other instruments have gone through a long progression of continuous improvement and evolution. It hasn't changed in fact, since the 14th century when it is called the Sackbut. The oldest surviving example of the instrument is from 1557 and is thought to have been made in Nuremberg.
The trombone is remarkably simple, consisting of a double length of metal tubing, two thirds of which are taken up by the characteristic slide mechanism, the remaining 3rd being the gradually expanding bell. The trombone comes in 4 sizes; alto, tenor, bass, double bass. Only the tenor and bass trombone's are common. Much of classical music composition has been ruled by tradition, and where trombones are concerned the tradition is that they don't sound good by themselves and should always be written for in the form of 2 tenor and one based trombone. It wasn't until Stravinsky that this tradition was broken with, for example in his Violin Concerto and Symphony of Psalms.
In general terms, the trombones are the natural base to the trumpets, as they both belong to the same family. However the trombone in some ways is more like a stringed instrument in that the production of the notes depends upon an exceedingly accurate here and a very fine adjustment of the movement of the slide (corresponding to the positioning accuracy of the fingers on the strings). In other words, unlike other brass and woodwind instruments, there are no set positions of valves or hold to produce the notes. This means that the musicians playing trombone door stringed instruments have to feel their way into notes. Also, much like stringed instruments, individual trombones differ from each other to a small but significant extent, due to variations in manufacturing and tube tolerances. This makes it a difficult instrument to play in an orchestra, but is what makes it such a brilliant instrument in a jazz band.
The trombone is difficult instrument to compose for, unless the composer is a trombonist themselves, such as Edward Elgar (1857 to 1935) and Gustav Holst (1874 to 1934). The difficulty is that there are 7 positions of the slide, each producing 7 notes (the fundamental notes of the tubing length). By varying the lip pressure a complete set of the harmonic series can also be obtained over each of these fundamentals, thus giving a complete chromatic series from B flat above middle C down to the 7th fundamental E. To be able to write good trombone music that is realistically practical to play, the composer must have in the head of knowledge of the position in which the player will have the slide at any particular moment. Without this knowledge, the trombonist may be asked to play a passage which looks ordinary enough in musical notation but may require impractical movements of the slide to get to the notes (this is called bicycle pump music by trombone is, as it is necessary to play the instrument like a bicycle pump to hit all the notes). A very similar situation exists for string players. A series of notes across strings can be played in different hand positions, first, 2nd et cetera positions, which are akin to the slide positions. A good piece of violin music can be played without changing position with time, or when changing position can do it in a logical sequence. But violin music is exceedingly awkward to play and as a result can sound scruffy. This is a particular problem for string quartets playing music for wedding ceremonies and wedding receptions. At a wedding the music is most likely to be arrangements of orchestral pieces, musics from shows, pieces of jazz and not string quartets by Mozart or Brahms. A piece written specifically for string quartet by good composer will take the issue of fingering into account. When arranging a piece of pop music orchestral music for string quartet to play at a wedding banquet, it's often impossible to cater for this, the music is often awkward to play.