“In a significant change in artistic authority, Philadelphia’s cutting-edge Relâche Ensemble will now be guided by two of its longtime musicians, easing out artistic and executive director Thaddeus Squire. In an announcement yesterday, flutist Michele Kelly and oboist/English hornist Lloyd Shorter were named co-artistic directors.” Squire, who has been credited with rescuing the eminent contemporary ensemble from near-collapse four years ago, had recently proposed expanding his authority, a change with which the musicians weren’t comfortable. Still, the split appears to have been an amicable one.