[kyoto kid]

...so curious.  The active skill, Performance is based on Charisma according to the core rules.

Now that makes sense for oration, acting, or singing.  However, what about playing a musical instrument like say a piano that is dependent on physical articulation, or dance which is based on balance and movement?  Wouldn't it make more sense that such forms of physical performance were based off of Agility?

[Michael Chandra]

I'd say it's possible for a GM to allow that. Note that the linked attribute is the default one, but asides from explicit exceptions, I see no reason for the GM not to state more. However, as with all houserules, communication with players is key.

[SpellBinder]

Previously this fell under Artisan, which was an Intuition based skill.

And also, Dance can fall under Gymnastics, which is an Agility based skill.  Wouldn't actually be a bad idea to mix them up, blending them somehow, since the gymnasts you see in competition are often doing both at the same time.

[Reaver]

Keep in mind the skill name here: PERFORMANCE.

This is not playing the piano, or singing in the shower...

This is doing something in front of a group of other people, and doing that well. It's "Showmanship" which is very much a charisma skill.... So much a charisma skill that there are Buskers you make good livings by doing things really BADLY! (but they are entertaining in their ineptitude).

This skill is more about achieving a desired narrative then a Pass/Fail, Yes/No result. And this talked about on page 141

USING PERFORMANCE
Performance is a Simple Test with a Social limit—the
gamemaster can use your hits to gauge the artistry of
your performance. If you’re trying distract a target, or
sweep them up in your performance, the generic modifiers
on the Social Modifiers Table (p. 140) apply, and
your target(s) use their Charisma + Willpower to oppose
your test.

[Xenon]

...what about playing a musical instrument like say a piano that is dependent on physical articulation

Performing with a Musical Instrument fall under the Performance skill which is linked to Charisma (Specific Musical Instrument is an explicit specialization to Performance).

Note that this skill is not just about playing the instrument. It is used to distract, captivate or sweep an audience up in your performance. I'd say Lindsey Stirling playing a violin is a great example of this: https://www.youtube.com/watch?v=RrutzRWXkKs or why not Jerry Lee Lewis (probably better clips than this but i cba to google atm) https://www.youtube.com/watch?v=ZD8YPY8RBQc

...or dance which is based on balance and movement?

Dancing in SR5 fall under the Gymnastics skill which is linked to Agility (Dancing is an explicit specialization to Gymnastics).

[Tecumseh]

I let my players link Performance to Agility when I feel it is relevant, like when  playing the drums.

[Mirikon]

My .02 Nuyen? Charisma is the linked skill for Performance, all performance, because there is a difference between a performance and technical proficiency. A guitarist can hit every note perfectly on the most complicated song you can imagine, but without the stage presence and charisma it just isn't the same.

Go check out some of the old episodes of Star Trek: The Next Generation, when Data is learning to play music. Technically perfect, but it lacks the soul that a less-perfect technician may have. It is the same reason why when you're looking at figure skating that the technical part is only a portion of the score. Performance is more than technique. Technique is important, yes, but without soul, then it is meaningless.