Conducting in music means beating time to help a group of musicians to sing or play well together.

If an orchestra is playing music, it is important that they all play exactly together.  They need to know exactly when to start, what tempo (speed) to go, how loud or quietly to play, and what the mood of the music should be.  If a small number of people play music together (like in a chamber orchestra), they can talk about this amongst themselves. One person can nod with his/her head or with the bow of a string instrument to help the group to start and finish together.

With larger orchestras, such as a symphony orchestra, there are so many people (almost a hundred of them in some cases) that they need a separate person to lead. This person is called the conductor.

In the 17th century, orchestras were usually small enough that they did not need a conductor. Often they were directed by the keyboard player or lead violinist. But as orchestras grew in size and began using a wider variety of instruments, it became a convention of having someone who was not playing any instrument to stand, facing the orchestra, as the director or conductor. One early conductor was the French composer Jean-Baptiste Lully (1632-1687), who beat time by banging a big stick (like a walking stick) on the floor to the time of the music. One day he banged his stick so hard, it went through his foot, and he died of gangrene.

Conducting as we know it today had become normal by the 19th century. The composer Felix Mendelssohn (1809-1847) was known to be a very good conductor as well. Some conductors in Victorian times behaved like they wanted to show off. At around the same time, Louis Antoine Jullien (1812-1860) was a French conductor who wore white gloves, which were presented to him on a silver tray at the start of the concert. He dressed in expensive clothes and his long black hair waved all over the place as he conducted. He was very successful, in France at first, in the UK afterwards, and then even in the US, where he worked with the showman P.T. Barnum. His concerts were a mix of dance and "classical" music, always with the best musicians. His life was so strange that a biography (in French) has been published ([1]).

The British conductor Sir Henry Wood (1869-1944), who was famous for conducting The Proms, was a well-liked man who was respected and loved by orchestras and audiences.

Conductors usually beat time with their right hand.  This leaves their left hand free to show the various instruments when they come in (when they start playing) and to give interpretative gestures, such as indicating when to play louder or softer, or faster or slower.  Most conductors have a stick called a “baton”.  It makes it easier for people at the back of large orchestras or choirs to see the beat.  Other conductors, such as those who lead singers, prefer not to use a baton.  A conductor stands on a small platform called a “rostrum”.

To be a good conductor is not easy. It is not just a question of giving a steady beat. A good conductor will know the music extremely well, understand how the composer wanted the music to sound, be able to figure out the technical details, and know how to be able to work with the orchestra to create great music everyone would want to listen to. Having good communication skills would help a lot, but some conductors speak very little during their rehearsals. They make everything clear through the way they conduct.

Some of the most famous conductors of the past were: Gustav Mahler, Hans Richter, Arthur Nikisch, Arturo Toscanini, Bruno Walter,  Wilhelm Furtwängler, Herbert von Karajan, Leopold Stokowski, Georg Solti, John Barbirolli, Otto Klemperer, George Szell and Leonard Bernstein.

Some of the most famous conductors today are: Marin Alsop, Riccardo Chailly, Gustavo Dudamel, Sir Simon Rattle, Andris Nelsons, Valery Gergiev and Bernard Haitink.

The main conductor who is in charge of an orchestra is often given the title "musical director".  This will usually mean that he or she has a lot of power in the organization of the orchestra, such as choosing the music that will be performed at each concert or inviting soloists to perform with the orchestra. Orchestras may give honorary titles to their conductor, such as "conductor laureate".

A "guest conductor" is one who conducts an orchestra regularly, but is not the main conductor. Typically, he or she would be invited by the main conductor to conduct a performance now and then. An "assistant conductor" will often be a young conductor who helps the main conductor and gets the chance to conduct some of the concerts. Leonard Bernstein became famous in 1953 as the assistant conductor of the New York Philharmonic when he led a concert, which was being broadcast nationally on CBS Radio, without having time to prepare for it. He would be the main director of that orchestra from 1958 to 1969.