Allow me to agree that the "pick one perform type per rank in perform" mechanic was kind of odd in the first place. But both the old and the new version of the perform mechanics are just a somewhat arbitrary decision. The 3.0 edition is a crude attempt to latch on some individuation on what falls under a single type of action. The 3.5 edition is a crude attempt at addressing the logical difference in cost to benifit between this and other skills.
For me, it's like the division between knowledge(arcana) and spellcraft. One's how much you know about spells on paper, the other's how much you know about spells as they're being cast. For me the mechanic "Identifying info about magic" covers both well enough. Maybe to someone else it makes a difference.
Can I ask something stupid? How much of an issue is this? How many people do you deal with who have multiple ranks in perform anyway? Heck, how many bards do you deal with? As far as my stuff goes, I'm the only bard I know of. My group asked me to play a bard in place of the other ideas I was tinkering with simply because they'd never seen anyone play a bard. So, at least as far as the games I'm in, or the people around me have been in, the perform skill hasn't come up much.
How big of an impact does perform have anyway? In the campaign I've been in, It's distracted some people so my allies could work, and made a few silver. I just don't see this as a large enough part of any given campaign to warrent more than a single skill. Maybe if I need to get into epic battles of musical prowress across a series of instruments, or if there's an actual mechanical difference, then I'd care. As far as I can see though, there's just no reason for it. You know, maybe if stringed insturments had an additional bonus to the duration of effects, but required more time, while comedy brought easy but short lived responses, while singing had a wider crit range, then there might be a reason for the difference. But otherwise you're asking me to expend a whole lot of skill points to keep my ability for multiple types of performance. As a bard, I've got a thin enough allotment of skill points (though 3.5 does alleviate this to a degree).
Frankly, I like Technik4's idea better. Divide up musical skills into a few discreet sets to follow the same model as weapon skills. Working with an instrument you're not proficient with provides a -4 to the perform check. Simple instruments could include: Singing, clapping, whistling, and telling tales. Musical instrumetns would include all the mundane stuff. Exotic instruments would include the gnomish electric axe and elven tree harp. Everyone could start with simple instrument proficiency. Bards would get musical instrument proficiency. Exotic instrument proficiency would be obtained via a feat. There would also be feats along the lines of the combat feats for instrument specialization and special techniques. This sticks with my gut feeling that a trained jack-of-all-trades musician should know the basics of a lot of instruments, keeps the skill used for "entertaining a crowd" one skill, makes sure odd instruments aren't easy to pick up and learn, provides measures for instrument specialization, and allows any normal person to be versed in whatever instrument they want, though it does have an opertunity cost.
Technic, this is my arguement to you. To me, it's simply a question of "How much time, energy, and detail is perform worth?" And I just don't think it's worth 9 separate skills. Personally, I don't think it's worth more than one skill in any of the games I've run or played. It's about entertaining a crowd, and nine times out of ten it doesn't matter how I do it.
Now, as far as the "if it's just about the perform ranks, just max one skill" line goes, my question is if you can gain the entire benifit of the skill from one, why have the division? What's the point?
I also happen to like the base instrument bonus idea, except for the fact that it's still just doubleing up on a pretty well unnecessarry skill.
Mostly, the difference in resolution just means that my DM can drop a magic keyboard in the game, and I'll have to debate getting a rank in keyboards next level. But unless it's a keyboard of "better than increasing my tumble" it'll probablly just go in the generic sell loot pile.
Now, if we were going to say, make Gitaroo Man D20 or Battle of the Bands D20, I'd be all up for something more complex.
Finally, a few stupid questions.
1. How do I act in combat?
2. How does dancing stop spells that need to be heard to have an effect from affecting my party?
3. How do I get a masterwork sing instrument?
I can't believe I complained that much about the freaking perform skill. What a waste of my evening.