Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for triggering music answer boxes. In one aspect, a method includes receiving a query, obtaining a plurality of search results responsive to the query, the search results being results from a search of web resources on the Internet, and determining from the plurality of search results that the query is a music query. Music data for a song responsive to the query is obtained, where the music data comprises a Uniform Resource Locator (URL) of song content of the song on the Internet. A music answer box is generated for the query, where the music answer box comprises the music data and a link to the URL of the song content, and the music answer box is provided in addition to search results.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for identifying entities that are related to an entity to which a search query is directed. One of the methods includes receiving a search query, wherein the search query has been determined to relate to a first entity of a first entity type, and wherein one or more entities of a second entity type have a relationship with the first entity; receiving search results for the search query; determining that a count of search results identifying a resource containing a reference to the first entity satisfies a first threshold value; determining that a count of search results identifying a resource having the second entity type as a relevant entity type satisfies a second threshold value; and transmitting information identifying the one or more entities of the second entity type as part of the response to the search query.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for receiving a first search query from a user device; receiving search results for the first search query provided by a search engine, wherein each of the search results identifies a respective resource; determining from the search results that the first search query relates to a first entity of a first entity type; determining that one or more entities of a second entity type have a predetermined relationship with the first entity; and transmitting information identifying the one or more entities of the second type to the user device as part of a response to the first search query.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for enhancing search results. In one aspect, a method includes identifying a plurality of registered publishers for enriched search results and, for each registered publisher, obtaining enrichment information from the registered publisher and associating the enrichment information with a resource provided by the publisher. A query is received. A plurality of responsive resources that are responsive to the query are identified. A first responsive resource is determined to be associated with enrichment information. An enriched search result is provided, the enriched search result identifying the first responsive resource and including the first responsive resource's associated enrichment information.