Voice classification in non-classical music the muscular, aerodynamic, and acoustical conditions in the larynx and in the vocal tract. The subglottal pressure, the driving force in phonation, needs to be adapted in accordance with the laryngeal conditions.” In other words, the very act of singing consistently within one technique or another literally causes the voice to physically develop in different ways, and thus change the timbre of that particular voice. Another example would be a coloratura soprano in opera. This is not only the highest female voice in opera, but also distinguished by its ability to do vocal acrobatic leaps, fast vocal runs and trills,
Singing to vocal range, vocal weight, vocal tessitura, vocal timbre, and vocal transition points such as breaks and lifts within the voice. Other considerations are physical characteristics, speech level, scientific testing, and vocal registration. The science behind voice classification developed within European classical music has been slow in adapting to more modern forms of singing. Voice classification is often used within opera to associate possible roles with potential voices. There are currently several different systems in use within classical music including the German "Fach" system and the choral music system among many others. No system is universally applied or accepted. However,