Put simply, the musical score is the written form of a composition. It uses a series of special symbols – musical notes – arranged on a stave, a set of five horizontal lines drawn across the page. Score derives from the vertical lines that connect successive related staves.
The symbols are like a musical language that musicians can read so they know what to play and when – much like we might read an instruction manual for a piece of flatpack furniture. The placement of the musical notes on particular lines or gaps between the lines in the stave indicate the pitch of the note, while which symbol is used shows how many beats each note should be held for.
Each musical note has a different name. The crochet, for example, is a single beat, while a minim is two and a semibreve is four. A quaver is half a beat and a semiquaver is quarter of one beat. There are also corresponding rests, which have their own symbols. Other notations include a dot next to a note, which indicates that it should be held for half as long again, so a dot next to a minim lengthens the note to three beats.
There are many other symbols which, among other things, determine the pitch range, the key, the time signature, the tempo and even how soft (piano) or loud (forte) the notes should be played. Learning all of this really is like learning a whole new language.
In an orchestra, each musician just has the score for their own instrument; this is usually referred to as a part. Only the conductor has the full or orchestral score comprising all the parts and it is up to them to bring all these different elements together in a coherent whole.
The orchestral score takes the form of a large book showing all the music for vocal and instrumental parts. It has to be big enough for the conductor to read during the performance, so in some cases it can be very substantial. It would be far too cumbersome for every musician to have a copy of the full score.
Two ways of reducing the full score to make it more manageable are the piano score or piano reduction and the piano-vocal score, sometimes called the vocal score. The former, as you might expect, is just the piano part. This can be written for a single player (two hands) or two (four hands). The idea is to reduce the entire score to two staves – linked by horizontal scoring lines – that can be played by a pianist (or two, if the reduction is for four hands). The vocal-piano score shows the full vocal work, including music and words, along with the piano reduction, usually for two hands.
It takes considerable skill to condense the full score to these smaller forms as they have to be simple enough for a single player to perform and yet accurately reflect the full piece. They are often used in rehearsals, so there is no need for the full orchestra to assemble. Usually this only happens with the full dress rehearsal.
The score for ‘Nessum Dorma’ from Puccini’s Turandot via Wikimedia Commons.