The reason why it is considered courageous for the musicians to play
"under the open sky" is because they are facing a dangerous situation.
<h3>What is Courage?</h3>
This refers to the quality that means that there is the strength to face fear and do the right thing.
Hence, it is important to note that for someone to display courage, then that means that they are facing threats or fear and need to overcome it.
Please note that your question is incomplete so I gave you a general overview to help you get a better understanding of the concept.
Read more about courage here:
brainly.com/question/26489684
i hope this helps you
from google:
"The Earth gets hotter as one travels towards the core, known as the geothermal gradient. Geothermal gradient is the amount the Earth's temperature increases with depth, indicating heat flowing from the Earth's warm interior to its surface. On average, the temperature increases by about 25°C for every kilometer of depth"