The most common and most likely answer to this crossword clue is the 6 letter word TWANGS
I've seen this crossword clue in Independent
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More clues leading to the result TWANGS
Buddy explains!

The straight part
We know that "sounds from banjo, maybe" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sounds from banjo, maybe = twangs.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 TWANGS mean?
TWANGS noun- The sharp, quick sound of a vibrating tight string, for example, of a bow or a musical instrument.
- A particular sharp vibrating sound characteristic of electric guitars.
- A trace of a regional or foreign accent in someone's voice.
- The sound quality that appears in the human voice when the epilaryngeal tube is narrowed.
- A sharp, disagreeable taste or flavor.
- To produce or cause to produce a sharp vibrating sound, like a tense string pulled and suddenly let go.
- To have a nasal sound.
- To have a trace of a regional or foreign accent.
- To play a stringed musical instrument by plucking and snapping.