Choral v Orchestral

Kind of an age-old topic, whether choral conductors are generally lousy orchestral conductors or whether there's even any difference -- it's been discussed on Choralist/Talk many times. Podium Speak suggests that orchestral conductors are also sometimes poor choral conductors, too:

Professional orchestral musicians are all extremely accomplished musicians who are the best available players of their instruments. Singers tend to put life and limb in the hands of the conductor. After having dozens of rehearsals with their chorus master for a show, it is a tricky thing for them to adjust to a new conductor, who is not giving them the attention that they were used to (specifically for cues and releases). Remember - most of these singers don't actually count, they are looking for the visual command (heck - it's not uncommon for them to practice mundane things like sitting, standing, lifting music and bowing on cue even - something you don't see in orchestral concerts). They are less concerned about the difference between subdivided two and a four beat pattern then they are about a consonant release or an offbeat entrance.

Cutoffs are another sticky matter: instrumentalists don't need to be told when to stop playing, not only because they can count, but because if they don't do it together, it isn't critical — but when a choir has a closing consonant on a cutoff, it is critical.

I find that I just conduct differently when I have instrumentalists: I give a clearer pattern, and don't play as many games with phrasing and "shaping" notes or phrases. The main reason is that the instrumentalists only get one or two rehearsals, so I can't afford any idiosyncrasies, whereas having a choir which knows me well allows me more, ahem, subtlety. I can use specialized gestures which remind them of particular things we worked on in rehearsal.