Siren

At 3rd level, you may sing and use your voice as a spellcasting focus. Additionally, you can amplify your voice, making it audible to ranges up to a mile. At 6th level, nothing can quell your voice. Words you speak or song cannot be affected by Silence or similar effects that would magically mute you.

Alluring Voice

At 3rd level, you learn Charm Person and Command. For you, they are considered bard spells and do not count against your number of bard spells known. You may additionally expend a Bardic Inspiration dice to cast either spell at 1st level without material components or expending a spell slot. When cast this way, the target is unaware that they were affected by magic.

When your Bardic Inspiration dice becomes a d8 you may cast them at 2nd level, d10 at 3rd level, d12 at fourth level, respectively.

Maritime Melody

At 6th level, as an action you may sing a ballad, rallying your allies. You and friendly creatures within 15 ft. gain temporary hit points equal to your Bard level at the beginning of your turn so long as you are singing. In addition, they gain a bonus to their saving throws equal to your Charisma modifier.

This effect lasts for 1 minute or until you break concentration (as if concentrating on a spell). Once you use this feature, you cannot use it again until you finish a short or long rest.

Harmonic Spells

At 14th level, you've learned to sing in two pitches simultaneously. When concentrating on a spell, you may choose to cast a second spell requiring Concentration so long as it is of 3rd level or lower, or begin your Maritime Melody, and concentrate on the two simultaneously. If you take damage or are affected in a way that necessitates a concentration check, you must make separate checks for each effect.

Once you use this feature, you cannot use it again until you finish a long rest.