A Handbook for Choral Conductors. 2nd, Expanded Edition by Don Moses, Robert Demaree, Jr, and Allen Ohmes.
This incredible book helps choral conductors faced with directing an orchestra understand how to approach the work, the orchestra, the rehearsal. 204 pp. Paperback.
Discusses the instruments and ways to meet the players' needs through 6 case studies:
Handel's Messiah
Bach's Magnificat in D
Vivaldi's Gloria
Haydn's Nelsonmesse
Schubert's Mass in G
Beethoven's Fantasia
If you are faced with this possibility or wish to enhance your skills, this book is one of few on the topic.