Some ensembles need 2 clarinets, some need 32...
In different ensembles you will find different types of clarinets; like one or two B flat clarinets in a chamber orchestra, or a wind quintet. A small harmony band or school band will have around 12 clarinet players while big wind bands or harmony orchestras need up to 30 clarinets of all different types.
In a symphonic orchestra a typical list of players would look like that:
ww (woodwind): 2, 3(1), 4(1,2,1), 2, ...
That means: there are 2 flutes, 3 oboes (more precise: 2 oboes and an engish horn, a bigger oboe), and four clarinets (one Eb-clarinet, two A/Bb-clarinets and one base clarinet), 2 bassoons ...
Where do you find the clarinet in the orchestra?
The seating of instruments in larger ensembles usually follows the pattern of the classical orchestra. People say it was introduced by Beethoven.
The basic idea is based on the necessity to place instruments by order of loudness. The players of the loudest instruments sit in the last row, the quietest in the first row. A violine will produce about 0,001 watt sinus with its strongest fortissimo; a flute 0,013 watt and a tuba 0,28 - that is 300 times louder than the violine! Because of the seating the audience can hear all instrument, since humans (and most animals, too) do hear sounds from nearby more prominently than distant sounds, even if the difference in distance is small and that of loudness is extreme.
- Classical orchestral seating
The seating is always looked at from the conductor. The classical order of the instruments goes from front to back and from left to right (some also say from more important to less important). The " concert master" is the first violinist up front on the left. The other first violins sit next or behind him, behind them you find the second violins (that usually play lower), then violas, violoncelli and Bases. The Flute (green) being the highest of the woodwinds sits left of the oboe (first row of woodwinds) and cor anglais or english horn (in yellow), then, depending on space on the stage, you have clarinets and bass clarinets (red) and then bassoons and contra bassoons (dark yellow) in the same row or behind. Brass (violet) may be one or several rows and percussion usually comes in the last row. A (grand) piano and the harp can be placed within the percussion group or sometimes set apart in the first row, the grand piano with the lid open to the audience and the harp player (95% girls, usually with long hair) placed to be seen well, too (if she is pretty ;-).
Following this general idea the clarinets usually are seated starting with the highest Eb, then 2 - 3 A and/or Bb (1st, 2nd, 3rd Clarinet), if needed there will be Alto and Bass Clarinet. Quite often the Bass Clarinet is played by the 3rd clarinet player, too.
You will find variations to this classical seating, because it has disadvantages, too: The first clarinet player sits behind the first flute, but far from the first oboe and the first bassoon. Delicate parts with only woodwind become much easier to play together if the 1st players of the wind instruments sit closely together (centered).
Sometimes the space on the stage limits the possible seating, you probably know the seating at "Last Night of the Proms" in London: Here all woodwinds sit in one single row. This means a lot of distance between flute and clarinet.
There is another disadvantage for clarinet players on the right in the traditional German seating: There you have trumbones and trumpets directly behind you. They can be very loud instruments, and they focus their sound straight foreward (quite different from e.g. French horns, you rather want to sit in front of those!). It results in sometimes physical pain in clarinet players' ears. Some professionals use ear protectors for some parts oftenly (no joke!).
As a rule, if a prominent solo part for clarinet is played within a piece, it will be the first clarinet player doing this (sits left/front of all clarinets except if there is an Eb-clarinet player, too). If you listen to a clarinet concerto like Mozart's, however, and have a solo player, this player will not sit together with the other clarinet players but will be standing in front of the stage, next to the first violins and the conductor like other solo concert players.
Clarinet players in the Wind Orchestra
Wind orchestras (like harmony bands, high school bands etc.) have no string section. The higher strings - that are violins and violas - are replaced by clarinets. In result there are many clarinet players in this type of orchestra, typically a solo clarinet, 4 first, 4 second, 4 third clarinets, an alto clarinet, two bass clarinets, occasional a counter bass or a counter alto clarinet. The seating of the orchestra however remains unchanged: Flutes and oboes left in front in the first row. The clarinet players usually sit in several rows behind this, next to them Bassoons. You add a set of saxophone players (soprano, alto, tenor, baritone). Saxophones blend in easily, so it is a question of taste and space where you put them (they fit in well with the french horns, too).
The brass section remains seated just like it is in the symphony orchestra. However, wind orchestras often have got a wideer variety of brass instruments (especially in the English tradition), like bugle, tenor horn and euphonium, and you find between trombones and tuba.
The counter base player (string base) typically takes a seat close to the tuba, this makes sense, because they usually have similar voices to play.
Clarinet players in dance orchestras, pop bands and big bands
In dance orchestras and pop bands as well as in big bands the clarinet player usually plays the saxophone, too, due to similar technique. In these formations you anyway will find only very few clarinets (only if a big band plays in the Glen Miller style. Big bands usually are seated in one or a few rows in order not to use up too many space in the hall which would be needed for dancing. But if there is a stage, you will find big bands and pop orchestras in classical seatings. Due to the widely used electronic amplification there is no need to arrange the players the classical way, therefore optical aspects will play a more prominent role. A full or double set of saxophones looks very impressive in a front row - but then again, a pretty violinist may as well sit in a prominent place.
Clarinet players in the wind quintett
The wind quintett is usually looking like:
flute, oboe, clarinet, bassoon, french horn
The players are sitting in a half circle that opens to the audience, which makes it possible they can all see and hear each other well (this ensemble has no conductor).
Clarinet players in pop music and big band
In pop music and the big band the clarinet was replaced more and more by the saxophone. The saxophone has got a couple of advantages: It is easier to learn, you can play louder and it looks better. Off course, you may say, that is a matter of taste, but a tenor sax is optically more impressive than a Bb clarinet. There are bass clarinets that look great, too, but you must sit to play them properly - how does that look on stage? The saxophone's disadvantage - a much narrower scale - usually plays no role in pop music.
By the way: If you want to join a band and they are interested, don't unnecessarily mention your classical activities, maybe just as "background experience". "Real" Jazz players don't take classical players seriously.
A Short Orchestra Sociology
(Don't take this paragraph too seriously!)
Within an orchestra you find groups and sub-groups, that have things in common and differ from each other, just like any other groups or sub-groups, too. These groups look at each other with certain prejudices, which are not fully valid, sometimes are really absurd, which may differ a little from each orchestra to the next but you will find that they are surprisingly stable all around the globe. They follow some patterns that are helpful to know.
Groups within the orchestra (extremely simplified)
An orchestra consists of strings and winds (we ignore percussionists, pianists and harp etc.) Sometimes there is a choir. These groups are musically separate, and they often even rehearse separately. If the orchestra should go into a restaurant after a concert, you will generally find the separate groups still sitting together without mixing. There may be exceptions to the rule, but they are rare.
This is the precondition for stable prejudices for the groups when looking at each other (that you will find in typical jokes on instrument players told all over): You will find that string players have started playing their instrument at the age of three, and they rehearsed hours and hours per day all their live. String players usually are tutti-players; that is, they impress as a group. While wind playing always is a compromise (between instrumental problems, technical problems etc.) it is possible for strings to play perfectly. They know it and often come very close.
In contrast, any wind instrument player (imagine a tuba player) will have started his instrument at the age of about 10 to 15. Maybe they rehearsed hard, too, but that is physically limited. Any one of them can be heard individually, even the third clarinet in its least important part. And while the string player packs away his instrument to go home to rehearse two more hours, the tuba player will cross the road and play on an Oktoberfest or in a jazz club, earning more than twice of what the string player got for the concert. The string player might compensate for this by feeling to be something better.
You will find the same views within the wind section between wood wind and brass. The wood winds will be looking down at the brass, while the brass will make jokes on the wood winds for being uncool. It is true that in classical music brass players usually have little to do (except for french horns), they usually have to count breaks. Typically an opera has got 32 pages for strings while the trumbones' part fits on one page - and most of that is in the last minutes...
Within the wood wind section the clarinet players are the most relaxed; their instrument is the only one that plays a considerable part in pop and jazz music. An oboe player or a bassoon player can't do much with his instrument outside the classical orchestra, except of founding a wind quintett (no wonder there are so many of them!). Clarinet players could as well play in a dixie land band or a tango ensemble or big band, if they like.
And then there is a special musical rivalry between oboe and clarinet: While in baroque the melody was passed from strings to flute to oboe and back to strings, the clarinet has joined this in the more modern music. Of all wind instruments the clarinet is the most flexible and nearly as expressive as the oboe. The best solo parts in classical music are parted between oboe and clarinet, the younger the piece, the more prominent the clarinet becomes.
In order to prevent misunderstandings: Really good musicians know, off course, that their effort only counts as team work. And even the triangle player can make or break the concert!