Empty Orchestra start singing. The music was pumped up and we had a mini party, with mad dancing – that was a memorable scene to film." The filming introduced a number of technical challenges, with the producer Adam Tandy explaining that the simultaneous singing and conversing made production particularly difficult: "To record it all 'clean' and have options in the edit, that was technically hard on everybody." Typically, karaoke scenes in television will see characters sing only the opening lines, but because of the format of "Inside No. 9", the characters in "Empty Orchestra" sing the whole song. Each character sang a
Empty set Empty set In mathematics, and more specifically set theory, the empty set or null set is the unique set having no elements; its size or cardinality (count of elements in a set) is zero. Some axiomatic set theories ensure that the empty set exists by including an axiom of empty set; in other theories, its existence can be deduced. Many possible properties of sets are vacuously true for the empty set. "Null set" is a distinct notion within the context of measure theory. In that setting, it describes a set of measure zero; such a set is not necessarily empty.