In my musical dictionary it tells me what a cadenza is, but I've lately been wondering about the history of the cadenza. It seems that in Baroque music-a Vivaldi concerto for example-there are no cadenzas. Did they start showing up in late Baroque, early Classical, late Classical...? Is it just a string instrument sort of thing or are there horn cadenzas, keyboard cadenzas, flute cadenzas, etc...? Not having listened to other instrument music as carefully as violin pieces I just don't know. Who was the first composer to include a cadenza?