A few tickets are still available (12/4 in Houston, 12/7 in Austin, and 12/8 in San Antonio) for a "Conspirare Christmas", the yearly psuedo Christmas concert. Shows include:  

12/3 Victoria, Texas

12/4 Houston, Texas

12/5 - 12/6 Austin (Sold Out)

12/7 - Austin, Texas (Long Center)

12/8 - San Antonio, Texas (Tobin Center)

For more information hit the source link above.