Getting good chops
The best chops come from clean, dry vocals with clear vowels. Long open sounds such as “ah”, “oh” and “ey” pitch well across a keyboard; consonants make good percussive accents. Look for chops that list a key, or tune them to your track before arranging them.
To make chops your own, try formant shifting, reverse reverb tails, and a touch of stereo widening. Playing the same chop at several pitches can build a melody that sounds sung but is entirely sampled.
Licences matter here
Vocals are where licence problems surface most: a recognisable voice is easy to identify, and uploads of famous songs are sometimes labelled as free by people who don’t own them. The badge on each card shows whether the licence was stated by the source or only by an uploader, so you can steer clear of risky sounds.