Conducting is the act of directing a musical performance by way of visible gestures. Orchestras, choirs and other musical ensembles often have conductors.
A conductor resident with an orchestra (as opposed to a guest conductor) who has involvement with the policies of an orchestra or opera company is sometimes known as a musical director, or nowadays by the German word Kapellmeister. Respected senior conductors (like senior instrumentalists) are sometimes referred to by the Italian word Maestro ("master").
History of conducting
An early form of conducting is cheironomy, the use of hand gestures to indicate melodic shape. This has been practiced at least as far back as the middle ages. In the Christian church, the person giving these symbols held a staff to signify his role, and it seems that as music became more rhythmically involved, the staff was moved up and down to indicate the beat, acting as an early form of baton.
From around the 17th century other devices to indicate the passing of time were used. Rolled up sheets of paper, smaller sticks and unadorned hands are all shown being used in contemporary pictures. The large staff remained in use at the Paris Opera, and was responsible for the death of Jean-Baptiste Lully - he hit his foot with the staff while conducting, and the wound became gangrenous.
In instrumental music, a single performer usually acted as the conductor. This could be the principal violinist, who used his bow as a baton, or a lutenist who would move the neck of his instrument in time with the beat. It was also common to conduct from the harpsichord in pieces which had a basso continuo part. In opera performances there were sometimes two conductors - one at the keyboard in charge of the singers, and the principal violinist in charge of the orchestra.
By the early 19th century, music had become sufficiently complex that it was desirable to have one person dedicated to conducting, not having to concern himself with performing as well. Accordingly, the baton became more common - this had the added advantage of being easier to see than bare hands or rolled-up paper by the orchestra, which was at this time expanding in size. Among the earliest notable conductors were Louis Spohr, Carl Maria von Weber and Felix Mendelssohn, all of them also composers.
A modern wooden conducting baton
Hector Berlioz and Richard Wagner were also conductors, and they wrote two of the earliest essays dedicated to the subject. Wagner was largely responsible for shaping the conductor's role as somebody who imposes his own view of a piece onto the performance rather than somebody who is simply responsible for ensuring entries are made at the right time and that there is a unified beat.
Since conducting is essentially a means of communicating 'real-time' instructions from the conductor to the performers, the only golden rule of conducting technique is that it should be clear and easy to follow. Aside from this, there are no hard-and-fast rules on how to conduct 'correctly', and a wide variety of different conducting styles exists.
There is a particular distinction between orchestral conducting and choral conducting. Orchestral conductors typically (though not always) use a baton, and giving a clear beat to the players is central. Choral conductors rarely use a baton, and although the beat is an important part of choral conducting, conductors tend to concentrate on musical expression and shape, making their movements appear more abstract.
Despite this wide variety of styles, a number of standard conventions have developed.
The beat of the music is typically indicated with the conductor's right hand, with or without a baton. The hand traces a shape in the air in every bar (measure) depending on the time signature.
For music in simple quadruple time (four beats in a bar), the hand traces down-left-right-up. For music in simple triple time (three beats in a bar), the hand traces down-right-up or, rarely, down-left-up. For music in simple duple time (two beats in a bar), the hand or baton traces down-up or down&right-up.
The two most important movements are the downbeat, which indicates the first beat of the bar, and the upbeat, which indicates the last beat of the bar.
If the tempo is slow or slowing, or if the time signature is compound, a conductor will sometimes indicate 'subdivisions' of the beats. For instance, in a particularly slow quadruple time, the conductor may beat down-and-left-and-right-and-up-and, where each 'and' is marked with a movement to an intervening point in the shape that is traced in the air.
Some conductors use both hands to indicate the beat. In this case, it is usual for the left hand to mirror the right hand's movements. The left hand is also used for turning pages in the sheet music and for indicating other aspects of expression.
Changes to the speed of the music are indicated simply by changing the speed of the beat. To encourage a particular accelerando or rallentando, a conductor may use additional body language such as leaning forward or back, increasing eye contact, making circling motions with the hands, or introducing beat subdivisions.
Dynamics are indicated in two main ways. Firstly, the volume of the music can be communicated via the size of the conducting movements: the larger the shape, the louder the sound. Secondly, changes to volume can be signalled with the left hand: an upward motion (usually palm-up) indicates a crescendo, a downward motion (usually palm-down) indicates a diminuendo. The former, changing the size of movements, often results in unintended tempo changes as well, that is, larger movements tend to slow down the tempo. Therefore, many conductors also change the tension of the hands, whereby the required change in size of movements is smaller. Loud dynamics would then correspond to strained muscles and rigid movements, while soft dynamics correspond to relaxed hands and soft movements.
Volume can be fine-tuned using various intuitive signals: for instance, showing one's palm to the performers in a 'stop' gesture, leaning away from them or putting a finger to the lips can be used to demonstrate a decrease in volume. In choral conducting, wiggling the fingers of the right hand is also an accepted signal for 'sing much more quietly'.
All these signals can be combined with eye contact or pointing to particular sections or performers in order to adjust the overall balance of the various instruments or voices.
Another important task for the conductor is indicating 'entries', i.e. moments when a new instrument or section joins the music. This is done either by pointing at the section at the appropriate time (though many orchestral players consider this poor etiquette) or by sudden eye contact combined with raised eyebrows. In the case of complex music where several parts enter simultaneously, the latter is obviously more practical.
Other aspects of musical expression are communicated by various body language signals.
Staccato and legato can be differentiated by more or less 'spikey' movements. Phrasing is indicated by wide overhead arcs or by a smooth hand motion either forwards or side-to-side. A held note is often indicated by a hand held flat with palm up, and the end of a note is denoted by the closing of the palm, the pinching of finger and thumb, or by tracing a rapidly-twisted spiral with a finger or baton.
Rules of thumb
A good conductor aims to maintain eye contact with the ensemble as much as possible, encouraging eye contact in return and increasing the general dialogue between players/singers and conductor. Facial expressions are also important; all performers, but especially less experienced ones, respond well to encouraging expressions.