query.sql

SELECT DISTINCT "song_id", "name", "tag_name"
  FROM (
    SELECT * FROM (
      SELECT "id" AS "song_id", "name" FROM "songs"
    ) AS "left" NATURAL JOIN (
      SELECT * FROM "song_tags" AS "left"
        NATURAL JOIN (
          SELECT "id" AS "tag_id", "name" AS "tag_name" FROM "tags"
      ) AS "right"
    ) AS "right"
) AS "songs_song_tags_tags"

veritas_many_to_many_through_join.rb

tags      = Relation::Base.new :tags, [ [ :id, Integer ], [ :name, String  ] ]
songs     = Relation::Base.new :songs, [ [ :id, Integer ], [ :name, String  ] ]
song_tags = Relation::Base.new :song_tags, [ [ :song_id, Integer ], [ :tag_id, Integer ] ]

SQL::Generator::Relation.visit(
  songs.rename(:id => :song_id).join(song_tags.join(tags.rename(:id => :tag_id, :name => :tag_name))).project([ :song_id, :name, :tag_name ])
).to_s

@dkubb yeah all those crazy queries are totally correct :) Good thing is that in many cases running a single query to eagerly load associated objects should be faster than running multiple separate queries for all the associations.