See more from Britains Got Talent at The 160-plus-piece choir from Wales had the audience and the Judges enthralled with their .\r \r The 160-plus-piece choir from Wales had the audience and the Judges enthralled with their mesmerising audition. But will their semi-final performance be the .\r \r Hallelujah! Its Côr Glanaethwy. The 165-piece Welsh choir brought the house down with their rousing semi-final performance. Could their magnificent rendition .\r \r See more from Britains Got Talent at The 165-piece Welsh choir brought the house down with their rousing semi-final performance.