[eric_t]

It would be much better if you could hum or whistle a tune, and it would recognize it. I saw a PhD thesis once about this, with an actual implementation that worked pretty well. The only problem was that the database of songs was very small. It's probably hard to scale this type of search.

[RiderOfGiraffes]

I remember once seeing a "dictionary" of songs. Each one was indexed by whether notes were higher, lower or the same as the previous note. Using D for down, S for same and U for up, and using # for the first note, here's the Start Spangled Banner ...

    #DDUUUUDDDUUSSUDDDDUUSDDD

Many, many tunes can be separated with the first 20 symbols.

Anyone have a reference? I'd like to acquire a copy ...

[wallflower]

SongTapper - surprisingly accurate - I think it works because it outsources a lot of the frequency/beat detection (to your brain/sense of rhythm)

http://songtapper.com

[dimbo]

The majority of people doesn't have an ear for music to correctly repeat melodies :(

[eric_t]

Exactly. But this algorithm was fuzzy, so it gave you a list of the songs which most closely resembled the one you tried to sing.

[dimbo]

I tried to use different "query by humming" services but the percentage of false positives (when a service produced a list of melodies and no one matched yours) was really huge. And even if the melody was in the list and you tried to find it again with the same service (by humming the same tune) the probability of getting it in the list again was pretty low.

Anyway, I think the idea of query by humming is not a dead end. However, such a hypothetical service should somehow collect and use a database of different "hums".