19th and 20th century composers occasionally had not used the tuba as a solo instrument. a. trueb. false

True
Is the answer
For example: John cage composed a piece known as the “Silence” which was performed at the Maverick hall, near Woodstock, New York. He sat down at the piano and he simply played a 43 minute piece composed for solo piano, so in this case fowardly speaking, no not all pieces contained a tuba

A.) is the

It is interweaving of the melodic lines with harmony