Detect the tone of the sentence "They were very happy to join the party".
The tone of the sentence "They were very happy to join the party" is positive and joyful.
Complete the following task based on the instruction and optional input provided.### Instruction:
Detect the tone of the sentence "They were very happy to join the party".

### Output:
The tone of the sentence "They were very happy to join the party" is positive and joyful.