the compositions from Snow White until 1961, when Bourne conveyed certain rights to Disney in settlement of litigation then pending between the parties. The jury rejected each of Bourne’s arguments.
Bourne’s second copyright infringement claim related to Disney’s use of the Compositions in television commercials. Bourne contended that the licenses granted to Disney did not provide Disney with the right to use the Compositions in these advertisements. The jury found in Bourne’s favor on this claim. In so doing, the jury rejected Disney’s argument that Bourne was estopped from asserting its interpretation of the license agreements. The parties stipulated to damages in the amount of $420,000.
On appeal. Bourne’s principal contention is that the district court erred in failing to enter judgment as a matter of law in its favor on its claim regarding Disney’s sale of videocassettes containing the Compositions. Bourne also argues that the district court improperly placed upon it the burden of proving that Disney’s use of the Compositions was unauthorized. Finally, Bourne appeals from the district court’s denial of certain ancillary relief in connection with its successful claim regarding the television advertisements. Disney cross-appeals, contending that the district court erred in failing to enter judgment as a matter of law in its favor on its defense of estoppel. Disney also takes issue with certain aspects of the district court’s jury charge. For the reasons that follow, we reject each of these challenges and affirm the judgment of the district court in its entirety.
BACKGROUND
1. The Agreements
- a. The 1933 “Shorts” Agreement
Since 1928, Disney has been in the business of creating animated motion pictures. These films include music, which is synchronized to the movement depicted in the drawings. During the 1930s, Disney was best known for creating six- to eight-minute animated motion pictures, called “short subjects” or “shorts,” featuring such characters as Mickey and Minnie Mouse, Goofy, and Donald Duck. At that time, Disney had no means of commercially exploiting the music featured in its shorts. In order to generate additional revenue from its musical compositions, Disney entered into an agreement with Berlin, one of the largest music publishers at that time.
Pursuant to a 1933 agreement between Berlin and Disney (“the 1933 Shorts Agreement”), Disney assigned the copyrights in the “musical compositions written for and used in connection with the synchronized motion picture comic cartoons of [Disney]” in exchange for a share of the revenues received by Berlin for use of the music. In derogation of the broad language set forth in the preamble of the agreement, paragraph nine limited the scope of the agreement in the following manner:
[T]he motion picture comic cartoons contemplated herein shall be the remaining twenty-six (26) motion picture cartoons to be produced for the motion picture season of 1933–34, plus the following motion picture comic cartoons comprised within the series produced for the motion picture season of 1932–33: [listing titles of seven cartoons].
In order to allow Disney to use its musical compositions in connection with the animations for which they were written, paragraph two of the agreement granted back to Disney
the right to record … such music, mechanically, and perform the license others to perform the same in connection with the respective motion picture for which such music was especially written, the right to record such music mechanically in any and all other motion pictures to be produced by [Disney], the right to ship, import and export … any and all such mechanical recordings throughout the world, but only in connection with [Disney’s] pictures. [Disney] reserves television rights in respect to its motion picture comic cartoons….
(emphasis added).
The 1933 Shorts Agreement was extended by the parties during the next several years. In 1935, the parties enlarged the subject matter of the agreement to include the musi-
