Tupac and Rihanna are among the most popular music artists in British prisons.
The late rapper topped a list of the most requested acts in 2012 on National Prison Radio, which broadcasts to 84,000 inmates across the UK.
Vybz Kartel placed second, K Koke third, Rihanna fourth and Drake fifth. Rihanna's inclusion makes her the only female artist to appear in the Top 20.
Eminem, Metallica, UB40, Evanescence and Pink Floyd are among the other acts who made the Top 20 most requested artists on National Prison Radio.
"Listening to something heavy can be a healthy release from prison life," an NPR radio host told The Mirror.
The Top 20 most requested artists on National Prison Radio are as follows:
2. Vybz Kartel
3. K Koke
8. Pink Floyd
9. Biggie Smalls
11. Jah Cure
14. Bob Marley
15. Lil Wayne