A major scale can be built on any note. In Lesson 8 you learned the D major scale. You now know all of the notes needed to play the G major scale.
This is the key signature for the key of G major. It has one sharp sign after the treble clef.
Because the G major scale contains the note F#, the key signature for the key of G major will consist of an F# note written after the clef.
Most songs can be played in more than one key. Here is a song you have previously learned in the key of D major. It is written here in the key of G major.
Here are some more songs in the key of G major. Remember to play all the C notes as C natural instead of C sharp.
Here is another duet for tin whistle and flute. Notice the use of first and second endings.