That decreases the chances of it to go down on the first hits is a passive skill called Prism. Though, if you keep getting beaten, you will drop the buff eventually. Same goes for any dance, and the passive for them is called Screen Dance. You should invest in both these two skills if you are serious about playing as a bard.
At parties before you get Mana Orbit, there are not much time for you to attack. If you are the only bard int the party. You can have one attacking and one doing Mana Cycle if you are two bards. Just make sure that the bard attacking is the one who has the dance skill up. Otherwise it will be a full time work keeping both dance and tambours up.
It is time for both bards to attack when you eventually get Mana Orbit. The key to success here is that the bards both get the Protect buff from a warrior in SRO. With this on you will almost certain never have to worry about getting hit. The passives to prevent the tambours and dances to go down are also high enough to cover if you do.