I loaned my magic book to one of our players, and won't get it back until we game on Sunday.

I have a street sam, and want to add a musical skill - like a piano playing lounge singer, who plays jazz, and classical music.

I know the MITS book has something on performance skills (for centering), but what would be the appropriate skill set, and linked attribute?

I was thinking it would be linked to Intelligence, but don't have my magic book to confirm it.

You need a knowledge skill (Piano, Sax, whatever) and the Centering active skill, whichever is lower is the number of centering dice you'll get.

Knowledge skills are based on Intelligence, and Centering on Willpower.

Perform: Kazoo

I guess my explanation was a little fuzzy... My street sam isn't looking for 'Centering' (couldn't have it anyway as he's mundane), just the skills to play music.

So I was wondering which attribute playing piano and singing would be linked to. I think it might be INT, but I'm not sure.
He does have a background knowledge skill of classical music, and I want him to have a Active skill(s) for playing piano and singing jazz and playing classical music.

The easiest thing to link musical skills to (even if you decide to make them active) would be intelligence. While manual dexterity, upper body strength and/or lung volume may play a part, memory (what does a dot on that line mean?) and perception (is this in tune?) play large parts and both fall under intelligence.

"Active" and "Knowledge" are really misnomers in how they divided the skills up. You have active skills such as aura reading and small unit tactics, while you have knowledge skills such as cooking or sculpture.

The way it seems to work is that skills of primary use to shadowrunners are called active skills, while skills of tertiary use, or hobby or mundane vocational skills, get lumped under knowledge skills.

So what I'm saying is, if you want a sammie who can sing and play the piano, you could probably take them as knowledge skills. I don't think they are any different than chemistry, professional bodyguarding, weightlifting, or forensics (all of which show up as "knowledge" skills for Archetypes in the main book).