The most common and most likely answer to this crossword clue is the 8 letter word MARIACHI
I've seen this crossword clue in The Daily Telegraph
M
A
R
I
A
C
H
I
More clues leading to the result MARIACHI
- Mexican music from aria: Chinese, partly
- Song introduced to male Greek character, a street singer
- Callas, say, Greek character who performs music
- Musical heroine with cold welcome for Mexican player
- Folk music from one American during parade on island
- Musical heroine, Greek character, street singer
- Mexican’s first song almost fashionable in this style?
- Musical nun joining Nile Rodgers’ outfit shortly to form band
- Street musician’s extraordinary charisma drawing one in as sun comes out
- I am rich, playing with a group of street musicians
Buddy explains!

The straight part
We know that "street singer" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case street singer = mariachi.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does MARIACHI mean?
MARIACHI noun- A traditional form of Mexican music, either sung or purely instrumental.
- A group that plays mariachi music.
- A member of such a group.
- Of or pertaining to a traditional form of Mexican music, either sung or purely instrumental.
- Of or pertaining to a band playing such music, or to the singers of such songs.