"God Save the Queen" (or King as appropriate) is the National Anthem of the UK, and also the National or Royal Anthem of several other UK territories and former Commonwealth countries. The melody in its current form was first published in 1744, but versions of the song date back to at least the early 1600s. Note that this same melody is also used for the US Patriotic Song "America" or "My Country 'Tis of Thee", which is a former US National Anthem. Another melody with similarities to this one was written by the Italian composer Felice Giardini (1716-1796) and is used to sing the Patriotic Hymn God Bless Our Native Land and other hymns including "Come, Thou Almighty King".
This arrangement is for piano and can be played on its own, or used to accompany singers and other instruments. Note that alternative songs are used at sporting events where the different counties which make up the UK are individually represented. These alternative British Anthems and the Anthems of other selected countries can be found in our article National Anthems and Patriotic Songs.