Music is digitised in several different forms, the most important of which are audio information and encoded notation. In principle, both of these can be used for retrieval purposes, but even in the easier case retrieval from encoded notation it is hard to attain meaningful output. One reason is that music notation maps musical events onto a two-dimensional space, only one of which (pitch) is generally employed for retrieval. The proportions of false positives and false negatives are both generally unacceptably high in pith-only searches. The obvious solution would be to take other parameters into account as well (at least duration), but methods for this are still in their infancy. An additional problem is that users generally want to search for similarity, not identity. A measure for musical similarity still needs to be found that satisfies computational and cognitive requirements.