What was the attitude of the Medieval Period/Early Renaissance Period Catholic Church toward the use of musical instruments in worship services? Why did they feel this way?

Sacred music in the Middle Ages was exclusively vocal. They refused musical instruments. Sacred music was solemn, strict, completely different from secular music. There was no division into musical measures, and no fixed rhythm.

Intuitism limited the use of instruments exclusively to support the singing of words, so that their meaning was well understood by listeners, and the souls of believers were sent to contemplate spiritual objects.

Explanation:

It took so long for US troops to enter combat because General Pershing sent the troops to camps in eastern France for more training so that they could amalgamate with British and French forces against a very strong German command of 260 divisions.Against that much force,the allies had only 169 divisions.

The solution came in the form of an agreement signed in December 1917.It read in compliance with the request of Great Britain and France, prompted by the expectation of a strong German offensive, the President agrees to the American forces being, if necessary, amalgamated with the French and British units as small as the company."The final decision on the level of amalgamation was left on Pershing to decide.The American troops did not sufficient time to learn about modern war, training of trenches,mobility etc.They also needed time build their relationship with British and French forces..