since the translation in question appears when searching for a German translation of interlude, I suggest a deletion of the entry.
AHD has the following for 'interlude', which definitely excludes Vorprogram:
1. An intervening episode, feature, or period of time: Kerensky has a place in history, of a brief interlude between despotisms (William Safire). 2a. A short farcical entertainment performed between the acts of a medieval mystery or morality play. b. A 16th-century genre of comedy derived from this. c. An entertainment between the acts of a play. 3. Music A short piece inserted between the parts of a longer composition.
as to the answer 'interlude' on searching for an English translation of Vorprogramm, this is, imo, wrong, and should, if at all, read: 'prelude', here AHD:
1. An introductory performance, event, or action preceding a more important one; a preliminary or preface. 2. Music a. A piece or movement that serves as an introduction to another section or composition and establishes the key, such as one that precedes a fugue, opens a suite, or precedes a church service.