D&D 5E The Hero (group class design exercise)

Recently, one of my friends said he didn't like the Bard class. I asked why, and he said it felt like a distinctly D&D character archetype and he didn't really see too many examples of characters you would call a Bard outside of things clearly copying bards, or from very specific cultures.

Now, I like the Bard, but I also like a good discussion, so I went along with it. He pointed out that the Bard's link to music, which is stuck there with it's automatic instrument proficiencies, get in the way of expanding the class into something more. I had before been talking about wanting to build a Warlord character with a Valor Bard, and maybe some fighter levels, but my friend was right; those three instrument proficiencies would feel oddly out of place on my character sheet.

I've always struggled at how to fit the Bard into my own setting. So we talked about it, and came up with the seed of an idea. What if some of the character tropes of the Bard were added to others to make the "Hero" class?

What is the Hero? They aren't the strongest. They're not the smartest. They might not even be the best. And they might not be the heart of the team. They have a little bit of everything, though. They're the "leader" in the five man band arrangement.

You see the hero as the protagonist in a lot of single player JRPGs. They aren't as limited in their powers as others, but they're also not as focused. The more I think about it, the Bard could really fit into this (though, personally, I would have made the Bard a halfcaster like the ranger and paladin, but that's just me).

Now, obviously, the name "Hero" wouldn't work. Every class in D&D can be a hero. But, I'm interested to see what kind of abilities one might put into such a class.

My baseline is a halfcaster, with magical secrets or another ability to poach spells from other classes. I imagine someone good at improvising, someone able to back up anyone, and someone with strong support abilities.

While I like your take on changing the Bard, I would like to offer a suggestion about the idea of Bards being limited to "music" and instruments. In our group, the current Bard/Paladin is a dwarf and he does oration and storytelling for his performances, some chanting old dwarven war songs is the most "musical" he gets. He has played the drums to offer cadence to his stories, but that isn't much really. This might be a culturally specific example, but is an option to get the Bard away from the wandering minstrel, etc. type.

Otherwise, instead of creating a new class, also how could this be accomplished by multiclassing with current classes? Your baselines sounds a lot to me like a Bard/ Rogue hybrid.

Who is he and why should we take his opinion seriously? Just because he can't see how the Bard can be different types of characters, doesn't mean anything. If I'm colorblind, does that mean colours are overrated?

On the topic of the 'Hero' class, I think its a bad idea. A class whose fluff is being the leader, the 'heart of the team', would just encourage players with the 'main character syndrome'.