The most common and most likely answer to this crossword clue is the 7 letter word SECONDO
I've seen this crossword clue in The Guardian
S
E
C
O
N
D
O
More clues leading to the result SECONDO
- Role of singer that comes in last bit of Idomeneo
- Duettist from Home Counties Tory party?
- Member of duo taking boy round City function
- . Contralto’s ending, say, in lower part of duet
- Musical part that you get with Prokofiev but not with Mendelssohn
- Outside of safe building with part for musician
- Contralto’s last bit is the lower part of two
- Part of a duet, a piece to harmonise con dolore
- Inferior leader of orchestra getting duet’s lower part
- Twinkling finale for virtuoso part in duet
Buddy explains!

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 SECONDO mean?
SECONDO noun- The second part in a concerted piece.