  Lyric-to-melody generation is an important task in automatic songwriting.
Previous lyric-to-melody generation systems usually adopt end-to-end models
that directly generate melodies from lyrics, which suffer from several issues:
1) lack of paired lyric-melody training data; 2) lack of control on generated
melodies. In this paper, we develop TeleMelody, a two-stage lyric-to-melody
generation system with music template (e.g., tonality, chord progression,
rhythm pattern, and cadence) to bridge the gap between lyrics and melodies
(i.e., the system consists of a lyric-to-template module and a
template-to-melody module). TeleMelody has two advantages. First, it is data
efficient. The template-to-melody module is trained in a self-supervised way
(i.e., the source template is extracted from the target melody) that does not
need any lyric-melody paired data. The lyric-to-template module is made up of
some rules and a lyric-to-rhythm model, which is trained with paired
lyric-rhythm data that is easier to obtain than paired lyric-melody data.
Second, it is controllable. The design of template ensures that the generated
melodies can be controlled by adjusting the musical elements in template. Both
subjective and objective experimental evaluations demonstrate that TeleMelody
generates melodies with higher quality, better controllability, and less
requirement on paired lyric-melody data than previous generation systems.
