In MP3 compression scheme, 60 minutes of music can be stored in about:

MP3 is a lossy audio compression format that typically encodes music at around 128 kbps, achieving roughly 10:1 compression compared to uncompressed CD-quality audio. At 128 kbps, one minute of audio is approximately 1 MB, so 60 minutes of MP3 music occupies about 50–60 MB of storage. Hence about 50 MB is the standard textbook answer for 60 minutes of MP3 music.