This is my first Build on Mobafire and i am sorry for spelling.
I've recently started playing Sona allot and i find her quite fun, i use a unique mastery setup that most people wouldn't touch on a caster but since i find it fun to be un-normal in my gamestyle i though id like to share it with other people.

Explanation of the Build.
Pros & Cons.
Personal opinion.
Tips.

Well to start with the Runes i use Mark of insight(0.95MP) for that extra kick in the spells

The Greater Seal of Replenishment(0.41/5 sec) for the Early game Mana ISSUES

The CD Reduction theres no need to explain that since all need CDR

and the Quints i start with the 2% XP yes meny ask why do that are you noob?! and
no its cause with the mastery it sets you to 7% more Xp Gained from creeps/minions etc....
so why not.

Second the 26 HP, with my mastery set up it will start you up with a nice hp amount 520 i think it is at lvl 1 = 5 bars and thats very good it gives you a bit more edge in lane.

last the Ability Power Quint that gives us 4.95 = 5 in-game + from my skill Hymn of Valor gives us a boost in AP early game + with the Magick pen means that you can harras and def to your liking.

The Mastery's i use is for like we all know casters = squishy goo under carry's feat thats why i take some extra juice so we can hurt them back. and in Utility i take the mana regen/Xp
and the most needed Utility master = 30% increased Blue buff.

Pros:
Great Support
Good damage
Good Farm
Great Harras
Can Solo Mid with no problem

Cons:
Squishy
Often Focused in team fights
Hard To 1v2 if you dont know what your doing

Ok here we go i like Sona she is Very Easy Mid Cause you can Heal Yourself And do Extra Dmg From
Her Passive that Doeas 14+9xLVL= alot of damage nad if you in hymn of valor you do 2x dmg= very good harras. i recommend to go mid since you get your gold faster then since in lane you halfto fight for last hits on minions so i stronly recommend mid.
summoner spells flash to get the F*** out of dodge when needed teletuby=teleport for getting fast back to tower so enemy dont out level you early game it can be a pain late game.
and since you have your spell=speed boost no need for ghost

Ok here we Go ASAP tell peeps your mid, so its easier that way ok now when your fighting in mid your gonna do the "Y0yo" tactic go forth hymn of valor run back do it 3 times so you can use your passive and remember to always have hymn of valor on so you do extra dmg.

ok the buy order is up to you i stay in lane till i can buy Chalis of harmony and the first boots that i later upgrade then i buy the complete sets.

ok now after you get to lvl 6 your stats should look like this 1/0/0 or 2/0/0
if it looks like above you can ask a team m8 to cover mid so you can run along and get blue buff.
ok well most games you will only get to will of the ancients and thats a good thing to get.
personaly you dont halfto get Void Staff i get it so i dont have to worry about irritationg magic resist

well if you have eny opinion pleas leav a comment and il try to answear ASAP and im always open to suggestions