import requests


def find_mime_type(url: str) -> str:
    """Determine the mime type of a file at the given url.

    Args:
        url: remote url to check
    Returns:
        Mime type - defaults to 'audio/mpeg'
    """
    mime = 'audio/mpeg'
    response = requests.Session().head(url, allow_redirects=True)
    if 200 <= response.status_code < 300:
        mime = response.headers['content-type']
    return mime