D&D 5E Bard's Instrument

[Baumi]

I have a question regarding Instruments for Bards, why do we need them in the 1st place?

You need them for spells that require a Material Component. But you can use a Component Pouch instead.

Do we need to play them to cast our spells ? cuz nowhere in the PHB E5 said anything like that.
The book just said Bards can use their Instruments as Focus Item.

You find the Rules under "Components" on Page 203.

We have to choose one casting style right?
For example I chose Verbal, it means that I cannot cast those spells who are not Verbal. Now as a Bard my Instruments give me extra advantage ? I can cast those non-Verbal spells with my Focus?

There is no such thing as a casting style.

Spells just have up to three necessary Components to cast it .. verbal, somatic and material. Each of them has a specific Requirment or you cannot cast it. You need to be able to speak for Verbal, have a hand free for Somatic (can be the same as the hand with the Focus) and a Focus or Component Pouch for the Material Component.

 

[Waterbizkit]

Baumi said everything I wanted to. I'd suggest re-reading the spell casting section of the PHB as well as the spell casting section for the Bard class.

As to the actual topic, I quite like the Bard Instruments and wouldn't have any compunctions giving them out to my players, if any of them were playing a Bard. People always like to rag on the guy/gal who's rocking the lute in the middle of a brawl, so I'm all for cool magical instruments so that they can truly melt some faces.