Miss Hall's testimony ended what the committees have termed the first phase of the inquiry after six weeks.
Miss Hall first performed both of her best known signature songs more than 60 years ago.
"They better be good seats," Miss Hall said to a friend, after he had moved on.
Miss Hall began to cry as the two watched the news conference.
Miss Hall had rolled up the documents and hidden them in her clothes.
Miss Hall recorded with Ellington on several occasions - in 1927, 1932 and 1933.
With her energy and curiosity, Miss Hall has herself become an indispensable reference.
Miss Hall said the original memorandums were kept in three different files, and she never had the chance to change all of them.
Miss Hall used to say that she was just no good at retiring.
Miss Hall began working in the library in 1960.