der Sänger
singer
A person who sings, especially as a profession or artistic activity.
Der Sänger der Band hat eine beeindruckende Stimme.
The singer of the band has an impressive voice.

singer
Loading your saved state.
singer
A person who sings, especially as a profession or artistic activity.
Der Sänger der Band hat eine beeindruckende Stimme.
The singer of the band has an impressive voice.

The word 'Sänger' (singer) comes directly from the verb 'singen' (to sing). The ending '-er' denotes the person (or animal) that performs this activity.
Wer gut singen kann, könnte ein guter Sänger werden.
Someone who can sing well could become a good singer.
Whether a human or a bird is meant is almost always clear from the context. With words like 'Band', 'Oper' (opera), or 'Konzert' (concert), it is a human. With words like 'Vogel' (bird), 'Nest', or 'Wald' (forest), it is an animal.
Der Sänger betrat die Bühne und das Publikum jubelte.
The singer stepped onto the stage and the audience cheered.
To specify the type of singer, the word is often used in compounds. Examples are 'Opernsänger' (opera singer), 'Popsänger' (pop singer), 'Rocksänger' (rock singer), or 'Straßensänger' (street singer).
Er träumt davon, ein berühmter Opernsänger zu werden.
He dreams of becoming a famous opera singer.
musician
'der Musiker' and 'der Sänger' both belong to the world of music. 'der Musiker' is the more general term: the person may play an instrument, sing, compose, or conduct. 'der Sänger' is more specific and means a person who sings. So a singer is often also a musician, but not every musician is a singer. The words can be confused when you are speaking generally about a person on stage. If the voice is important, 'Sänger' is more precise; if it is generally about making music, 'Musiker' is more natural.

Der Sänger hatte eine sehr klare Stimme und sang ohne Mikrofon.
The singer had a very clear voice and sang without a microphone.
Nach dem Konzert sprach Tom mit einem Musiker aus der Band.
After the concert, Tom spoke with a musician from the band.