What is another word for lower register?
Pronunciation: [lˈə͡ʊə ɹˈɛd͡ʒɪstə] (IPA) 
Lower register refers to the lower range of a musical instrument or a person's voice. Some synonyms for this term include bass, deep, low-pitched, or baritone. The distinction between "lower register" and these synonyms can depend on the specific context, and the type of instrument or voice being discussed. For example, "bass" and "low-pitched" may be used more commonly to describe the lower range of a string instrument, while "baritone" may be used to describe a lower range of a male voice. Similarly, "deep" may be used more generally to describe a deep or resonant sound, regardless of its range.
