In general, content creators and owners support copyright legislation, as it almost always benefits them. A current supporter of copyright in the US is Utah Senator Orrin Hatch, who as a songwriter, is a member of ASCAP.
You need to contact ASCAP. The American Society of Composers Authors and Publishers.
Only if the song is a free domain song, such as "Happy Birthday" or "God Save the Queen". Popular songs, such as songs which are owned and copyrighted by an artist can only be used with written consent from the copyright holder, unless your organization holds an ASCAP license, in which case, the ASCAP logo must appear on the page containing the music which is being used under the ASCAP license you hold.
The venue needs a license from the performing rights organizations, such as ASCAP and BMI.
Performance rights are generally handled by the performing rights organizations, ASCAP and BMI.
You would need a performance license; in the US this is easily obtained from ASCAP, BMI, and SESAC.
Contact the copyright holder and ask for a license. The quickest way to find the copyright holder is through the performing rights organizations, ASCAP and BMI. Both PRO's websites have extensive information on this topic.
No. If you write something, you automatically own the copyright to your work (unless you have previously assigned it to someone else). However, copyright is just the first step in being able to collect royalties from your work. Performance-rights organizations like ASCAP, BMI and SESAC are (ostensibly) in the business of collecting royalties from the live performance or playback of copyrighted music (in public venues, on radio, television or on the internet) and distributing the royalties that they have collected to the composers and publishers, proportionally to the size of the audience and the number of times the music is played.
You would need a license from a performing rights organization. In the US, most works are handled by ASCAP or BMI.
For information on registering with ascap, see the related link below.
Composers, rather than publishers, are members of copyright societies, so there are Boosey properties in multiple licensing groups. For Boosey NY, the majority are ASCAP; for Boosey London, most are PRS; Bote & Bock would be GEMA; and so on.
The written work is automatically protected by copyright.