This exotic rapier has a beautiful treble clef shaped into the hilt.  Somehow, a sentient creature named Aldolpho has been bonded to this blade.  You have a +1 bonus to attack and damage rolls made with this magic weapon which is as light as a feather and weighs nothing.  The sentience within the blade allows you to invoke an Elven magic called the Bladesong, provided that you aren’t wearing medium or heavy armor or using a shield. It graces you with supernatural speed, agility, and focus.

You can use a bonus action to start the Bladesong, which lasts for 1 minute. It ends early if you are incapacitated, if you don medium or heavy armor or a shield, or if you use two hands to make an attack with a weapon. You can also dismiss the Bladesong at any time (no action required).

While your Bladesong is active, you gain the following benefits:

• You gain a bonus to your AC equal to your Intelligence or Charisma modifier  (whichever is higher, minimum of +1)

• Your walking speed increases by 10 feet.

• You have advantage on Dexterity (Acrobatics) checks.

• You gain a bonus to any Constitution saving throw you make to maintain your concentration on a spell. The bonus equals your Intelligence or Charisma modifier (whichever is higher, minimum of +1).

You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses of it when you finish a long rest.

Proficiency with a Rapier allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Magic, Elf or Half Elf, Damage, Combat, Finesse, Vex