seems like he has a bit of a taste 4 old heavy metal but also a ghost album on his wall? something thats like a mixture of chiptuney 8 bit video game stuff with a heavy guitar would work, think Tensei's music on Homestuck

Tensei - Dance of Thorns (https://www.youtube.com/watch?v=3dKRKDn9ZJk)

some reasonably old heavy metal songs I think hed like

Iron Maiden - Aces High (https://www.youtube.com/watch?v=Xg9aQvjMS60)

Dio - Stand Up and Shout (https://www.youtube.com/watch?v=P_vIQ8-gF3A)

Black Flag - Rise Above (https://www.youtube.com/watch?v=wDUYCyajDcs)