| MUSCLEFISH | Muscle Fish | http://www.musclefish.com/ |
| MELDEX | University of Waikato's New Zealand Digital Library | http://www.nzdl.org/ |
| THEMEFINDER | Stanford University | http://www.ccarh.org/themefinder/ |
| QPD By-Content Music Indexing Project | Carnegie-Mellon University | http://www.link.cs.cmu.edu/qpd/ |
| SEARCH BY HUMMING | Steven Blackburn, University of Southampton | http://audio.ecs.soton.ac.uk/sbh/ |
| CATFIND | University of Hong Kong, Yip Chi Lap | http://zodiac.csis.hku.hk:8192/catfind/Music/ContentSearch.html |
| MiDiLiB | Dr. M. Clausen, Univ. of Bonn | http://leon.cs.uni-bonn.de/forschungprojekte/midilib/english/ |
| TUNESERVER | Rainer Typke | http://name-this-tune.com |
| Scribe | LaTrobe University, John Stinson | http://www.lib.latrobe.edu.au/AudioVisual/Stinson/about.html |
| HUMDRUM | Ohio State University, David Huron | http://dactyl.som.ohio-state.edu/Humdrum/guide01.html |