IOWA CITY -- Chicago new-music ensemble eighth blackbird has built a fine reputation, and lived up to that billing at the Englert Theatre on Wednesday night (2/6/13). This is a lively, talented group of six musicians who are very well matched in their abilities. New-music can be quite demanding, and this gang plays very well together. They obviously enjoy each other's company. And we enjoy being in the theater with them. The Hancher program was wildly varied, featuring seven composers, six of whom are American. The best-known composer of the evening was Phillip Glass ("Knee Play 2" from "Einstein on the Beach"), with an 8-minute segment of one of his major works. Ironically, it was the weakest piece of the evening. Of interest to aficionados, perhaps, but not particularly successful. Another well-known composer in new music circles is Gyorgy Ligeti, with "Etudes for Solo Piano," arranged for the sextet. It is a very difficult work to perform, with swiftly changing dynamics. It is also a difficult work to listen to. However, eighth blackbird artists have remarkable charisma to go along with their musicianship, and their energy and commitment is most persuasive, even if the music is tough sledding. The ensemble engages the audience right away, and holds onto us for a couple of hours. What the artists play is often impossible to comprehend at first hearing, but it urges us to keep listening and to identify promising composers. They are the scouts out ahead for new sounds, for explorations that may produce a different way of hearing and apprehending our sonic environment. I applaud their quest and value what they are up to. Last night's concert offered much to enjoy. "Pieces of Winter Sky,"  a piece commissioned by Hancher in league with the Music Accord consortium, is evocative of an environment Iowans know all too well: a cold, harsh winter. At times it reminded me of sleet hitting my face in sub-zero weather. At the same time, it has a kind of calm inside: lonely and still, with the quiet beauty of the end of a winter storm. In the midst of the blizzard created by Pulitzer Prize-winning composer Aaron Jay Kernis, birds are trying to sing, trying to find their voices. And, thankfully, they do. Their music will survive. Commissioned works are almost always a roll of the dice, as you never quite know what you'll get, even if you support the very best artists. But it's a suitable activity for an enlightened presenter like Hancher Auditorium, if ambitious music is to have a future. I also liked the new work by Andy Akiho that concluded the program. A steel band percussionist, Akiho has created a terrific composition called "erase," that ends with very strong drumming by Matthew Duvall. It is a perfect "closer" for an eighth blackbird concert. Please be on the lookout for this remarkable band of committed music-makers. They are up to something good.