A student comes to a lesson with a question: “My band director said to do it this way. Is that wrong?” Now you're trying to reconstruct a rehearsal you weren't in, using a thirteen-year-old's summary.
A quick exchange with the director would probably help. Finding time for it during the week is harder.
Ask about the same passage
Imagine a student receiving different instructions about the release in the same audition excerpt. Instead of asking the student to decide which adult is right, compare the edition, marking, and intended result.
Different articulations in different pieces are not automatically a conflict. A student may simply need help recognizing when each approach is appropriate. Ask what they were told and in what context before treating it as contradictory advice.
What needs work before the concert?
A director can share performance dates, audition requirements, and a few passages needing attention. A private teacher can share a current technical focus and any relevant difficulty affecting ensemble playing.
Be precise enough to help: “Please check the rhythm entering measure 47” is more actionable than “the section is behind.” Include an excerpt or measure reference through an appropriate, permitted sharing method.
Private lessons may also serve goals beyond the ensemble. Discuss those priorities with the student and family rather than assuming every lesson should become rehearsal support.
A message someone has time to answer
At the start of a term, exchange preferred contact details and agree on what warrants an update. A short message when a significant issue or milestone arises may be more workable than a report after every lesson.
A useful update could contain three things: the current focus, an observation, and a request. For example: “We're working on consistent releases. The short excerpt was controlled today. Are you hearing the same improvement in rehearsal?”
Agree with the family and school on appropriate recipients and communication arrangements. Keep musical updates focused on the student's work. A broad shared spreadsheet is not automatically a suitable place for personal concerns.
If visits to rehearsal would help, arrange them through the school's procedures and with the director's agreement. The visitor's role should be clear before they enter the room.
Ask the student to explain what they are trying in lessons and where it applies in ensemble music. When terminology differs, demonstrate the sound each instruction is aiming for.
For expectations at the program level, see What to Expect From Your Private Lesson Providers.