1. A system, comprising: one or more hardware processor devices; and storage storing computer-executable instructions which, when executed by the one or more hardware processor devices, cause the one or more hardware processor devices to: receive a message from a particular user; determine whether the message includes a selection control command specifying a target media item to be played by media playback equipment, or a non-selection control command; in a first instance where the message is determined to contain the selection control command: send the message as an input query to a search system, receive a query response to the input query from the search system, the query response identifying a top-ranked media item, and control the media playback equipment to play the top-ranked media item on the media playback equipment; and in a second instance where the message is determined to contain the non-selection control command, control the media playback equipment based at least on the non-selection control without interacting with the search system.
1. A system, comprising: one or more hardware processor devices; and storage storing computer-executable instructions which, when executed by the one or more hardware processor devices, cause the one or more hardware processor devices to: receive a message from a particular user; determine whether the message includes a selection control command specifying a target media item to be played by media playback equipment, or a non-selection control command; in a first instance where the message is determined to contain the selection control command: send the message as an input query to a search system, receive a query response to the input query from the search system, the query response identifying a top-ranked media item, and control the media playback equipment to play the top-ranked media item on the media playback equipment; and in a second instance where the message is determined to contain the non-selection control command, control the media playback equipment based at least on the non-selection control without interacting with the search system. 2. The system of claim 1 , wherein the computer-executable instructions further cause the one or more hardware processor devices to: provide one or more instances of a collaborative user interface presentation for use by users in a group of users, including the particular user, each instance of the collaborative user interface presentation revealing messages entered by the users in the group.