There’s a piece called ‘Pifa’ in the middle of Handel’s ‘Messiah’, which is played only by the orchestra. The ‘Pifa’, which takes its name from the shepherd-bagpipers, was used as a music title not only by Handel but also by other contemporary composers. It was a kind of convention. Corelli, a composer of the Baroque era, also composed a ‘Pifa’ in his concert grosso. It is quite interesting if you compare it with Handel’s ‘Pifa’ while listening.