Let me tell you about Bernie’s best two parts.
1-He is humble, and he is not timid about asking for help. .
2-He really loves music.

“Filling in the holes” Yes and a bit more. In Latin music they are very careful to fill in the holes with rhythmic vocals. In fact, I would have to say their rhythm is the most important. It is difficult to sit till when it is played.

Comping is not normally taught because it’s a come naturally, most feel it, they do not think about.
1-Kansas City here I come -------------- Here is where the singer needs help. You come in lightly, then grow, and then play your comping with a flavor that helps them get into their next part. Singers favor compers who help lead them to the next part AND, do not comp while they are singing; it can interfere with their phrasing. Some musicians voice their chords with the melody on top. Singers hate that, they know which note THEY WANT to sing, and when they want to sing it. No leading lines or comping while someone is singing unless it is part of what made the song popular. t

Bernie, when asked what to use to comp I was told, “What would like to hear”. It is all about listening; not copying but listening and trying.
All fill ins and comping are different for each style of music.

John C.