91398
Sometime around 1700 , a fourth key ( G ♯ ) was added , and it was for this type of instrument that composers such as Antonio Vivaldi , Bach , and Georg Philipp Telemann wrote their demanding music .
 Antonio Vivaldi, Bach, Georg Philipp Telemann
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Antonio Vivaldi, Bach, Georg Philipp Telemann