"Her melody moves the soul, her silence sunders the body."
Swain, after attending her concert.

Sona, The Maven of The Strings, is a beautiful champion that plays for you, if you understand me. She is able to synchronize her abilities with the game, creating an unique play style which gives to you and your allies the melody to win!
In this build, I create two different styles of playing with Sona, the Arpeggio, my Huntress Sona (more general) and the Ostinato, my Support Sona (more in-depth) guide.

So... Let's Rock!

Power Cord: After casting 3 spells, Sona's next attack deals extra 14 + (9 x level) magic damage. This enhanced attack has an additional effect depending on which spell was cast last.

• Staccato: Her next attack will double the damage of her Power Chord.
  
• Diminuendo: Her next attack will debuff the target to deal 20% less damage for 4 seconds.
  
• Tempo: Her next attack will slow the target by 40% for 2 seconds.
  

Power Chord Is a great passive if used correctly. Gives extra damage on the next attack depending of Sona's stance.

Arpeggio: Uses Power Chord combined with the Hymn of Valor and Lich Bane to gives MASSIVE damage on her next attack. If the enemy is running, use Song of Celerity to Tempo slows the enemy (great if combined with Rylai's Crystal Scepter).

Ostinato: This can be good with The Ostinato (support Sona) depending the situations, for example: Tempo can help your allies to catch the enemy and Diminuendo can help your weak allies to avoid to be dead (or help your friend Talon and his passive).





Hymn of Valor:

• Persistent Aura: Sona plays the Hymn of Valor, granting nearby allied champions bonus attack damage and ability power until she changes stances.
  
• Activation: Sona sends out bolts of sound, dealing magic damage to the nearest two enemy champions or minions.

Hymn of Valor is your "huntress" skill. Gives to you and the nearby allies extra damage and ability power, and activating it deals massive damage with great AP ratio(70%) to two nearby enemies.

Arpeggio: Use it to deals massive damage to the enemy and activates Lich Bane and Power Chord, dealing MORE MASSIVE DAMAGE!!!

Ostinato: Use it to get some minions and level up faster, after all, this is a support Sona. You can stay it activated to gives extra AD/AP for your allies.






Aria of Perseverance:

• Persistent Aura: Sona plays the Aria of Perseverance, granting nearby allied champions bonus armor and magic resistance until she changes stances.
  
• Activation: Sona sends out healing melodies, healing herself and the most-wounded nearby ally champion. Additionally, both Sona and the healed champion will have the bonuses of this aura doubled for 3 seconds.

Aria of Perseverance cannot be the best healer, but still is good. You can use it to heal Sona and her allies and giving extra Armor/MR.

Arpeggio: Use it when you have low HP (well, your heal will heal a lot :D). You can combo Aria of Perseverance and Song of Celerity to hunt the enemy (for example: you catch a Teemo and heals your self by the damage dealt by his poison).

Ostinato: Well, my support build doesn't give AP to Sona... But her aura... Yes! With your items, these aura will make your allies immortals!!





Song of Celerity:

• Persistent Aura: Sona plays the Song of Celerity, granting nearby allied champions bonus flat movement speed until she changes stances.
  
• Activation: Sona energizes nearby allies with an additional burst of speed for 1.5 seconds.

Song of Celerity can be a great skill if the word is Chase. You can call this "Nitro". When Sona activates her Nitro you and your bros run like a Torreto, catching your target and hunting and owning it!

Arpeggio: Use it to help your hunts and runaways. Tempo can slow the enemy, and gives to you a great advantage (extra speed, enemy slowed? *-*)

Ostinato: If you and your allies are winning an epic battle and your enemies are running, combine this with Shurelya's Battlesong to run like a Fast and Furious movie.





Crescendo: Sona plays her ultimate chord in a broad line in front of her, forcing enemy champions caught to dance stunned for 1.5 seconds and take magic damage over the duration.




This skill have a great AP ratio (80%) and FORCES YOUR ENEMY TO DANCE!!!!


Arpeggio: DANCE AND DIE, OR RUN AND DIE, MAKE YOUR CHOICE! \m/

Ostinato: You can use it to force to dance your enemies, helping your team on the epic battle.


Credits to League of Legends Wikia for the gifs.

Ignite: Well, this SS is very good when the word is "Hunt". Deals true damage to the target, and kills those enemies whose life was 1 when they finally go away. You can switch this with Exhaust if you don't like ignite.

Ghost: This SS can be very helpful (you know, hunt and kill or run and avoid to be killed).




Clairvoyance: If you are a support, this SS can help you and your team to create an estrategy or avoid ganks. If you want, switch it with Fortify.

Heal: I'll not explain this SS. You know what this thing does and doesn't need any explaination e.e.


I can't say many things about the Summoner Spells, in fact, SS' are for your own waste. I like Exhaust, maybe you don't. '-'

Rylai's Crystal Scepter: She cannot be so benefited with this, however, is of great help when it comes to hunting. The extra Health gives to Sona extra survivability. But this item needs a lot of synchrony, because Sona only has two damage skills (the other two aren't benefited with the slow, duh). Use them and synchronize with Tempo to perform a great kill.




Boots of Swiftness: Boots vary from person to person, so this is just my suggestion. I don't use boots of mobility because this is an ambush item (Great for Teemo, Shaco and all of the stealth champions). But if you are planning to hunt, get Boots of Swiftness.




Lich Bane: This is the Arpeggio item. Gives to Sona extra Ability Power, Movement Speed and... Power Chord bonus! Stack the power chord with the lich bane effect to perform extra damage to the enemy. As I said earlier, Stacatto with this deal MASSIVE DAMAGE!!




Archangel's Staff: The "big eye" is very flexible with Sona. It stacks the extra mana using skills, right? Well, how Sona is a speller, it stacks very fast! And the extra AP from mana is great. This big eye can be helpful with the Ostinato too (well, you can't help your friends with no mana e.e).




Rabadon's Deathcap: This "Harry Potter film" item is the best item (and the most expensive) for AP Champions. It gives AP and... MORE AP LOLOL... How this item spends a lot of money, I prefer to create it in long games (or if you are on a Killing Spree and doesn't spent any money). Rabadon's Deathcap, in my opinion, it's a final item (you should not start with it, think about it).



Now, the 6th item: I never could finish my guild, so I decided that Force of Nature was a nice item, but I was wrong. Sona already have a spam heal, so why use it? Now that I know it, let's get some nice items at end game for Sona. This last item depends a lot the other team, you need to buy it mid game ONLY if you need it. Now let's see some options.



Now, if you don't like to read, here is some of strands of the Arpeggio scale.



And this is it.

Aegis of the Legion: Unique aura: +12 armor, +15 magic resistance and +8 attack damage to nearby allied champions. This item is very simple to be made, you can use it when your team have squishy champions. This item is very cheap, like the other aura items. But the Ostinato have a great gap, you can't die. Well, you know, you are a support, if you die, who will help the poor Teemo? I forget it. Aegis of the Legion can be combinated with Aria of Perseverance (can combine with Hymn of Valor).




Soul Shroud: Unique aura: +12 mana regeneration per 5 , +10% cooldown reduction to nearby allied Champions. This item doesn't help just you, help your allies! The mana regeneration and the CDR can help all of your allies. Well, this is useless if all of your team are manaless, but the CDR still help them. Mana Manipulator is your primary item, It's cheap and helps on earlier games.




Shurelya's Reverie: Unique: Nearby champions gain 40% movement speed for 3 seconds (60 second cooldown). This is a different type of aura, you need to activate it. But don't worry, it's easy to use. The extra movement speed combinated with Song of Celerity is great if used correctly. As I said earlier, you and your allies run like a Torreto's movie LOLOL.




Will of the Ancients: Unique aura: +30 ability power and 25% spell vamp to nearby allied Champions. This is a perfect item for spellvamper champions like Katarina, Akali and Vladimir (ok, can be good for you too, but they're better e.e). The Aura Spellvamp is UNIQUE, but I tested and you and your ally can make this, the aura aren't UNIQUE *-*, in other words, Sona and her friend, vladmir can have 50% spellvamp together! This aura can be stacked with Hymn of Valor.




Stark's fervor: Unique Aura: +20% lifesteal, +20% attack speed, and +30 health regeneration per 5 to nearby allied champions. Unique aura: -20 armor to enemies. This is a different type of aura items. Some Aura items buffs your team (like Aegis of the Legion) and some aura items debuffs your enemy (like Frozen Heart) but this item is mist. Ok, cannot be a good item for Sona, but a support doesn't think about itself, think about your allies.




Frozen Heart: Unique aura: -20% attack speed to nearby enemies. Now we start with the another type of aura, the debuff aura. This item can be expensive, but is very good. Gives to Sona cooldown reduction, armor and mana, can be easily used instead Archangel's Staff on the Arpeggio .



Abyssal Scpepter: Unique aura: -20 magic resistance to nearby enemies. I don't recommend this item for the Ostinato, but can help your team against tankers or a feeded Warwick. You can use it for the Arpeggio or when you don't have any options (or you have it, but you prefer to combine the Arpeggio style with the essence of the Ostinato :D).

PS: The term "stacked" was used with the motive of combine the skill with the aura.
PS2: Mana Manipulator and emblem of valor aren't listed because they make the listed items Soul Shroud and Zeke's Harbinger, successively.




Well, the support for your allies are here, but.. what about your own support? If Sona only gets aura items, she will be weak, so, another thing that a support needs is survivability. The Arpeggio in G is different, because only gives this, but why make an imortal Sona if she doesn't help anyone?.


Now, a history. What is tenacity? "Tenacity reduces the duration of Crowd Control effects by a percentage. Note that items providing Tenacity will not stack with each other in any way, but it will stack multiplicatively with champion abilities that grant Crowd Control reduction." Let's see an exemple of League of Legends Wikia:

" Irelia with Mercury's Treads, Cloak and Dagger and 3 enemy champions nearby will get a 35% CC duration reduction from items and an additional 40% reduction thanks to her Ionian Fervor, reaching 1-((1-0.35)*(1-0.40))=61% reduction, with either Cloak and Dagger or Mercury's Treads's bonus not contributing at all, so there's no point in having two or more Tenacity items."


In short, you just need one Tenacity item. Make your choice:

• Mercury's Treads: These boots are probably the best option. But you decide this.
• Eleisa's Miracle: If you get another boots, this is another viable option, because can be switched with Shurelya's Battlesong (the both are made with the same item, the philosopher's stone).
• Moonflair Spellblade: This is not recommended, but...
• Cloak and Dagger: Forget it, this is useless for Sona.

Tenacity solves one of your problems and gives you one problem? (What?). Well, If you want Tenacity in your inventory you'll need to make some changes, like:

• You can use Mercury's Treads to get your tenacity or Ionian Boots of Lucidity to get your CDR. The both are good, but if you get your Ionian the other item with CDR should be Shurelya's Battlesong, but this item make the same path with...
• ... philosopher's stone, that makes the another good tenacity option, Eleisa's Miracle, losing your extra CDR from it. BUT... the another item that makes Shurelya's Battlesong is the Kindlegem, that makes a good item for Sona, the cheap and good Spirit Visage, that I'll speak later. (later means now :B)

I don't have time to make builds, so i'll finish this later... but i'll not forget it ok?:B

@EDIT: Arpeggio Path added
jhoijhoi lines added (thx for the contribution \o/)

@EDIT: Ostinato Path Aura items added
Ostinato Path tenacity items added

@EDIT: Force of Nature removed from Main Items.