Difficulty level, roughly compared to ABRSM exam grades. 0 is beginner, 9 is advanced (beyond grade 8).
In the best tradition of supplementing our own repertoire with great pieces for others, Toke-Lund Christiansen has arranged this famous work really well for us and it will probably find its way onto the concert platform soon. It’s hard but playable. The piano reduction is Bizet’s which makes this an even more interesting hybrid. Definitely worth the money.