Georg Philipp Telemann (German: [ˈɡeːɔʁk ˈfiːlɪp ˈteːləman]; 24 March [O.S. 14 March] 1681 – 25 June 1767) was a German Baroque composer and multi-instrumentalist. He is one of the most prolific composers in history, at least in terms of surviving works. Telemann was considered by his contemporaries to be one of the leading German composers of the time, and he was compared favourably both to his friend Johann Sebastian Bach, who made Telemann the godfather and namesake of his son Carl Philipp Emanuel, and to George Frideric Handel, whom Telemann also knew personally.

Almost completely self-taught in music, he became a composer against his family's wishes. After studying in Magdeburg, Zellerfeld, and Hildesheim, Telemann entered the University of Leipzig to study law, but eventually settled on a career in music. He held important positions in Leipzig, Sorau, Eisenach, and Frankfurt before settling in Hamburg in 1721, where he became musical director of that city's five main churches. While Telemann's career prospered, his personal life was always troubled: his first wife died less than two years after their marriage, and his second wife had extramarital affairs and accumulated a large gambling debt before leaving him. As part of his duties, he wrote a considerable amount of music for educating organists under his direction. This includes 48 chorale preludes and 20 small fugues (modal fugues) to accompany his chorale harmonisations for 500 hymns. His music incorporates French, Italian, and German national styles, and he was at times even influenced by Polish popular music. He remained at the forefront of all new musical tendencies, and his music stands as an important link between the late Baroque and early Classical styles. The Telemann Museum in Hamburg is dedicated to him.

Telemann was born in Magdeburg, then the capital of the semi-autonomous Duchy of Magdeburg within the Electorate of Brandenburg, in the Holy Roman Empire. His father Heinrich, deacon at the Heilig-Geist-Kirche (Magdeburg) [de], died when Telemann was four. The future composer received his first music lessons at 10, from a local organist, and became immensely interested in music in general, and composition in particular. Despite opposition from his mother and relatives, who forbade any musical activities, Telemann found it possible to study and composed in secret, even creating an opera at the age of 12.

In 1697, after studies at the Domschule in Magdeburg and at a school in Zellerfeld, Telemann was sent to the famous Gymnasium Andreanum at Hildesheim, where his musical talent flourished, supported by school authorities, including the rector himself. Telemann was becoming equally adept both at composing and performing, teaching himself flute, oboe, violin, viola da gamba, recorder, double bass, and other instruments. In 1701 he graduated from the Gymnasium and went to Leipzig to become a student at the Leipzig University, where he intended to study law. He ended up becoming a professional musician, regularly composing works for the Nikolaikirche and even St. Thomas (Thomaskirche). In 1702 he became director of the municipal opera house Opernhaus auf dem Brühl, and later music director at the Neukirche. Prodigiously productive, Telemann supplied a wealth of new music for Leipzig, including several operas, one of which was his first major opera, Germanicus. However, he became engaged in a conflict with the cantor of the Thomaskirche, Johann Kuhnau. The conflict intensified when Telemann started employing numerous students for his projects, including those who were Kuhnau's, from the Thomasschule.

Telemann left Leipzig in 1705 at the age of 24, after receiving an invitation to become Kapellmeister for the court of Count Erdmann II of Promnitz at Sorau (now Żary, Poland). His career there was cut short in early 1706 by the hostilities of the Great Northern War, and after a short period of travels he entered the service of Duke Johann Wilhelm, in Eisenach where Johann Sebastian Bach was born. He became Konzertmeister on 24 December 1708 and Secretary and Kapellmeister in August 1709. During his tenure at Eisenach, Telemann wrote a great deal of music: at least four annual cycles of church cantatas, dozens of sonatas and concertos, and other works. In 1709, he married Amalie Louise Juliane Eberlin, lady-in-waiting to the Countess of Promnitz and daughter of the musician Daniel Eberlin. Their daughter was born in January 1711. The mother died soon afterwards, leaving Telemann depressed and distraught.

After around a year he sought another position, and moved to Frankfurt on 18 March 1712 at the age of 31, to become city music director and Kapellmeister at the Barfüßerkirche [de] and St. Catherine's Church. In Frankfurt, he fully gained his mature personal style. Here, as in Leipzig, he was a powerful force in the city's musical life, creating music for two major churches, civic ceremonies, and various ensembles and musicians. By 1720 he had adopted the use of the da capo aria, which had been adopted by composers such as Alessandro Scarlatti. Operas such as Narciso, which was brought to Frankfurt in 1719, written in the Italian idiom of composition, made a mark on Telemann's output.

On 28 August 1714, three years after his first wife had died, Telemann married again, Maria Catharina Textor, daughter of a Frankfurt council clerk. They eventually had nine children. This was a source of much personal happiness, and helped him produce compositions. Telemann continued to be extraordinarily productive and successful, even augmenting his income by working for Eisenach employers as a Kapellmeister von Haus aus, that is, regularly sending new music while not actually living in Eisenach. Telemann's first published works also appeared during the Frankfurt period. His output increased rapidly, for he fervently composed overture-suites and chamber music, most of which is unappreciated. These works included his 6 Sonatas for solo violin, known as the Frankfurt Sonatas, published in 1715. In the latter half of the Frankfurt period, he composed an innovative work, his Viola Concerto in G major, which is twice the length of his violin concertos. Also, here he composed his first choral masterpiece, his Brockes Passion, in 1716.

Telemann accepted the invitation to work in Hamburg as Kantor of the Johanneum Lateinschule, and music director of the five largest churches in 1721. Soon after arrival, Telemann encountered some opposition from church officials who found his secular music and activities to be too much of a distraction for both Telemann himself and the townsfolk. The next year, when Johann Kuhnau died and the city of Leipzig was looking for a new Thomaskantor, Telemann applied for the job and was approved, yet declined after Hamburg authorities agreed to give him a suitable raise. After another candidate, Christoph Graupner, declined, the post went to Johann Sebastian Bach.