A New Book by Simon Horobin records a previously unknown gathering in which Tolkien shared for the first time fragments of his Elvish poetry, in the early 1930s.
To know more:
https://www.telegraph.co.uk/books/authors/tolkien-lord-of-the-rings-narnia-cs-lewis-oxford/
https://www.english.ox.ac.uk/article/simon-horobins-new-book-sheds-light-on-relationship-between-cs-lewis-and-john-betjeman