The difference between the two musical works is the music type, melody and rhythm.

1. Music type: The Spring Festival Overture is a traditional Chinese music piece, performed by an orchestra, with the theme of celebrating and welcoming the Spring Festival. Joyful is a cheerful children's song with a festive and joyful atmosphere as its theme.

2. Melody and rhythm: The melody of the Spring Festival Overture is more solemn and exciting, and the melody fluctuates greatly, giving people a solemn and enthusiastic feeling. The joyful tunes are more cheerful and lively, and the melody is simple and easy to remember, suitable for children to follow and participate.