Beethoven wrote a concerto for this instrument in D major, and Niccolo Paganini wrote 24 caprices for this instrument.
Henri Vieuxtemps and Henryk Wieniawski were both performers and composers for this instrument.  Edouard Lalo's Symphonie Espagnole is a five-movement solo piece for this instrument, while the composer of La Campanella was a virtuoso for it and developed left-hand pizzicato for it. Beethoven wrote a concerto for this instrument in D major, and Niccolo Paganini wrote 24 caprices for this instrument. Notably featured in Antonio Vivaldi's The Four Seasons, for 10 points, what is this instrument, the highest-pitched member of the string family?
Henri Vieuxtemps and Henryk Wieniawski were both performers and composers for this instrument.  
violin