The above demo uses Schubert's "Ständchen" recorded by German soprano Emmy Bettendorf (1895-1963) as starting point for finding similar melodies in the database. The closest match proves to be the same Emmy Bettendorf recording, though by examining the metadata, the title "Serenade" indicates a different publisher. The system has effectively found a duplicate of the same melody.
The next closest match, by Swedish tenor Jussi Björling (1911-1960), is the same melody, though an octave lower. This is followed by British tenors Webster Booth (1902-1984) and Frank Titterton (1893-1956). Note that the matching melody recorded by Titterton is located at 98 seconds in the track, as it is the second instance of that same melody in the track. The recording by John McCormack, 112 seconds into the track, is the same melody, but this time at a different pitch, a semitone higher. The system can accurately deliver similar melodic patterns, regardless of pitch or octave.
The first 6 tracks listed are versions of the same piece; 'Serenade' or 'Ständchen'. Having run out of the exact same melody, the system will match melodic sequences which are similar to the sampled melody. In recordings by Gerhard Hüsch and Lotte Lehman we can detect a similar style in the rendition of another Schubert piece.
The final match offers a surprise finding: a reading of Shakespeare's 'Henry V' by Welsh poet W J Gruffydd. On analysis, it becomes apparent that Gruffydd hits the very same notes that Schubert wrote.
Content courtesy of Dan Leech-Wilkinson and the King's Sound Archive, University of London.