Question

I read that one can support query by humming by using MIDI files. Can someone please give me an idea on how this can be done?

Answer 1

If you have access to IEEE Library: Query by humming of midi and audio using locality sensitive hashing

Quoting from Query by Humming of MIDI and Audio Using Locality Sensitive Hashing, audio retrieval examples

We propose a query by humming method based on locality sensitive
hashing (LSH). The method constructs an index of melodic fragments by
extracting pitch vectors from a database of melodies. In retrieval,
the method automatically transcribes a sung query into notes and then
extracts pitch vectors similarly to the index construction. For each
query pitch vector, the method searches for similar melodic fragments
in the database to obtain a list of candidate melodies. This is
performed efficiently by using LSH. The candidate melodies are ranked
by their distance to the entire query and returned to the user. To
retrieve audio signals, we apply an automatic melody transcription
method to construct the melody database directly from music
recordings.