The tenor range is classically C3 to C5 — two octaves spanning from the C below the bass clef staff up through the C above middle C. Trained tenors often extend to D5 or E5; some lyric tenors hit F5 in head voice or with mix. The signature isn't the absolute top — it's the ability to sustain *full voice* into the upper passaggio (the register transition around F4-A4 for a tenor) without flipping into falsetto.
The lower-tenor distinction matters: if your bottom comfortably extends below C3 (the C below the bass clef staff) but you struggle to sustain notes above F4 in full voice, you're likely a baritone, not a tenor. Baritones can absolutely sing pop and rock — most male pop singers are baritones — but the *technique* required to nail high notes is different. Baritones use mix voice; tenors push more chest weight into the same register.
The four main classical tenor subtypes: (1) Tenor leggero / lyric tenor — light and agile, range C3-C5+, repertoire like Don Ottavio in Don Giovanni. (2) Lirico spinto — fuller weight, range C3-C5, capable of dramatic moments. (3) Dramatic tenor (Heldentenor in German) — heaviest, often extending to D5 with sustained power, Wagner roles. (4) Countertenor — uses falsetto/head dominant production to access alto range, technically a separate classification.