Different standards exists and each have their merit for different types of music. From working in studio sessions and TV and concert performances with symphony orchestra I’ve adopted the bullet proof standard of marking each double barline with a big enclosed bar number acting as the rehearsal mark.

Each bar number is still shown at the centre of each bar at the bottom of the score – closest to the conductor:

Some conductors/orchestra prefer only to show bar numbers once at the start of every system, but this seems to take up much navigational time during rehearsal. This can also lead to momentarily confusing layout coinciding with page numbers.

Knowing that each barline is marked gives also the security that if the rehearsal mark is missing in printing, the conductor still has the barline and corresponding bar number to go about. This also makes the enclosed rehearsal marking in the score redundant but marking them in the parts is crucial to fast navigation along with sufficient bar numbering.

Mark away!