A typical theatre built for musicals would have a "pit". The pit is where the musicians play from and the musical director would sit on a podium, from which they would be able to see the orchestra below them and the actors on stage above.

Have a look at this musician's guide of their pit for Wicked. They are quite crammed in!

In the early days of Broadway, musicals would typically use a full "classical" orchestra for shows and the pit would be crammed full with strings, woodwind, brass and percussion.

• Listen to "People Will Say We're In Love" from Oklahoma at the Proms and you will be able to hear the big, recognisable Broadway (and Hollywood) sound. It lends a luscious aspect to the music.

• Phantom of the Opera debuted on the West end in 1986. Though this show included a similarly large orchestra, it also uses synthesisers. Listen for the pulsating quavers that play from 0'20 to give the song a feeling of terror and passion as Christine sings about being entranced by the Phantom.

• Rent opened on Broadway in 1994. Notice that the orchestra in "Take Me Or Leave Me" is condensed to a band of piano, electric guitar, bass and drums in place of any orchestral instruments at all. This modern approach allows the flirtatious song to come to life in a refreshing way.

These days, orchestrations tend to vary depending on the show. Hamilton, for example, is orchestrated for a small string ensemble alongside a typical pit band.

These days, to save space, keyboards are sometimes used to replicate orchestral instruments with sampling. Furthermore, instrumentalists often have to play more than one instrument to save space in the pit.

Being able to aurally recognise the instruments above is important, in terms of the effect they have on the emotion and drama at any given point in the song. Though some come across more subtly (the harp is not very noticeable), here are some notable examples:

• Guitar with overdrive is commonly used at the beginning of the song. At bar 11 (0'17) it brings an epic and lofty sound to the accompaniment. The first chorus from bar 40 (1'29) is also a good example.

• The use of lower brass (trombones + horns) on the chordal motif at bar 20 (0'32) gives the music a warm sound that is very broad, allowing the mood to shift from being angry to more calming.

• The use of woodwind (clarinet + flute) from bar 24 (0'43) is more subdued than the preceding brass and brings a more intimate sense of tenderness.

• Synths are played by the keyboard and often add a unique element of excitement. They often play the quaver response in the motif e.g. bar 23, 1'13. Listen out for the unusual futuristic synth providing a weird timbre in the second chorus from bar 80 (2'36), adding to the sense of wonderment.

• The use of tremolo strings adds a sense of nervous energy to the first verse at bar 34 (1'16), contributing to the growing sense of agitation.

• The ostinato in the first chorus (bar 51, 1'52) is played by pizzicato violins and a synth to allow it to stand out distinctly.

• The bass clarinet is used in the bridge to add to the sense of mystery, providing a mellow contrast to the more sparkly sound of chimes and glockenspiel heard at the same time (bar 88, 2'48).

• The bassoon and its distinctive timbre is heard at bar 113 (3'48) to add contrast to the underscore at this point.

• Tubular bells are used at bar 147 (4'52) to add to the sense of climax.

• The horn plays from bar 163 (5'17) with a descending melody that sounds contemplative, adding to the sense of anticipation before the final section.

The electric guitar, bass guitar, piano and drums make up the rhythm section. Their role is to drive the music forward by comping, keeping the momentum going and providing the harmony.

The drum kit plays many fills to go between sections which adds an even great sense of drive. Bar 59 (2'02) is a good example. The snare drum has a lot of reverb added to it giving it an epic sound suitable for the song. It is used quite sparingly and is first heard from bar 62 (2'09).