Orchestral Suite No. 3 in D major, BWV 1068 - 6. Gigue

Johann Sebastian Bach (31 March [O.S. 21 March] 1685 – 28 July 1750) was a German composer and musician of theBaroque period. He enriched established German styles through his skill in counterpoint, harmonic and motivicorganisation, and the adaptation of rhythms, forms, and textures from abroad, particularly from Italy and France. Bach's compositions include the Brandenburg concertos, the Mass in B minor, The Well-Tempered Clavier, two Passions, keyboard works, and more than 300 cantatas, of which nearly 100 cantatas have been lost to posterity. His music is revered for its intellectual depth, technical command, and artistic beauty. [source from Wikipedia]

"Air on the G string" is selected from the second movement of "Orchestral Suite No. 3" of Bach. This music with the character of singing and the simple and flowing melody is frequently used as the solo performance on the concert by the musicians, and makes people cannot refrain from singing along.