It's amazing when you consider how brillant they where at writing music... they were light years ahead of everyone in their era.
The scale runs that Bach created in his classical music could still revival many of todays best great jazz guitarist.
The reason I say that is Bach wrote what could be considered tons of lead scales into his classical songs.
But this is long before guitarist had jam sessions.....Both Bach and Beethoven invented modern music... even though we still call it classical.
....It's amazing todays artist can't survive without computer software to time out the music they write...and many artist also some kind of digital recorders to slow down and figure the timing on fast riffs and ect.....but these guys did it first in their heads !!