KEY MAJOR SCALE
Scales refer to a series of notes that go in an ascending and descending manner. The major scale is the foundation from which all other scales are formed. A C major scale begins with a C and ends with a C. The same rule applies with the rest of the keys where a D Major Scale begins and ends with a D and so on. The notes on a major scale is numbered from 1 to 8, this signifies the intervals. - internet
The Major Scale is the most popular amongst the flute beginner. For easy playing and handling they prefer middle Key range such as the Key G Major to start with.
Below are some of the audio samples for some major keys as indicated. Please help your self to listen to the tune and mark the differences. As the rule of thumb, the lower the key, the longer the flute and the mellower the sounds.