The difference between Countertenor and Tenor

Countertenor as a noun:

adult male singer who uses head tone or falsetto to sing far higher than the typical male vocal range

Countertenor as a noun:

male singing voice far higher than the typical male vocal range

Countertenor as a noun:

(Older) a part or section performing a countermelody against the tenor or main part

Tenor as a noun (music):

A musical range or section higher than bass and lower than alto.

Tenor as a noun:

A person, instrument or group that performs in the tenor range.

Tenor as a noun (archaic, music):

A musical part or section that holds or performs the main melody, as opposed to the contratenor bassus and contratenor altus, who perform countermelodies.

Tenor as a noun:

The lowest tuned in a ring of bells.

Tenor as a noun:

Tone, as of a conversation.

Tenor as a noun (obsolete):

duration; continuance; a state of holding on in a continuous course; general tendency; career.

Tenor as a noun (linguistics):

The subject in a metaphor to which attributes are ascribed.

Tenor as a noun (finance):

Time to maturity of a bond.

Tenor as a noun:

Stamp; character; nature.

Tenor as a noun (legal):

An exact copy of a writing, set forth in the words and figures of it. It differs from purport, which is only the substance or general import of the instrument.

Tenor as a noun:

That course of thought which holds on through a discourse; the general drift or course of thought; purport; intent; meaning; understanding.

Tenor as a noun (colloquial, musici):

A tenor saxophone.

Tenor as an adjective:

Of or pertaining to the tenor part or range.