Everyday Muscle.

Vocalis

The fine-tuner of your voice — acts as the medial part of thyroarytenoid to precisely control individual vocal cord segments for singing and speech.
Function
Adjusts tension of vocal fold segments for fine pitch control
Origin
Vocal ligament and inner thyroid cartilage
Insertion
Vocal process of arytenoid cartilage
Innervation
Recurrent laryngeal nerve (CN X)