Every song should be tagged with descriptions, for example: strong female voice, acoustic, ballad, slow tempo that way you can decide whether you wanna listen to a specific song from an album or browse for similar songs based on a particular element you like.
Hello and welcome to the community!
There are a couple of ideas similar to your, already in the community: https://community.spotify.com/t5/Spotify-Ideas/Integrate-Last-fm-tag-data/idi-p/706651 and also https://community.spotify.com/t5/Spotify-Ideas/Tag-Music/idi-p/57185
You may also like the idea suggested about adding notes to songs, http://community.spotify.com/t5/Spotify-Ideas/Adding-Notes-to-songs/idi-p/24865
Please add your kudos and comments to the ideas if you like them.
Tags would be another form of meta data which would need to be added by the labels/artists/record companies. In general Spotify does not have the resources to add meta data to all tracks.