Beginning with the New York Philharmonic concert season of 1958-59, Leonard Bernstein offered his audience a departure from the normal concert experience. He included an informal talk in the first concert of a week's series, which he called a Thursday Evening Preview. Usually given at the beginning of the concert, but sometimes between pieces, the brief talks covered a variety of topics, often centering on the techniques, styles and compositional school of a composer whose work was featured that evening; or on a topical subject such as American or other national style in music. Bernstein adapted both his concerts and the format of his talks to audience response in order to sustain the intimate, informal atmosphere he desired. The talks became less frequent after their initial season but continued until 1964.
Typically, the documentation for each talk is a handwritten draft and a typewritten script with handwritten emendations and annotations. Musical examples or additional materials are rare.