The solo concerto became popular with composers like Antonio Vivaldi (1678-1741) who wrote over 400 concertos for various instruments. His most famous concertos are a group of four known as "The Four Seasons". These are violin concertos, and each concerto deals in turn with one of the seasons: spring, summer, autumn and winter. Many other Baroque composers wrote concertos: Johann Sebastian Bach (1685-1750) wrote several concertos for violin although only two have survived, the others have been lost. He also wrote solo concertos for the harpsichord. George Frideric Handel (1685-1759) wrote concertos for the organ. Organs in England were very small in those days and balanced well with an orchestra. Handel sometimes put pauses in his concertos where the soloist could improvise (make up) some music. These improvised bits became known as “cadenzas”. Concertos ever since have cadenzas where the soloist can show how brilliant they are at playing and at improvising. Some composers wrote their own cadenzas.