Complex sentence: As of his 2007 appearance, he has performed there 40 times and there is only two other venues he has played more shows (Tweeter Center and Merriweather Post Pavilion).
Split into simpler sentences: As of his 2007 appearance, he has performed there 40 times. There are only two other venues at which he has played more shows (Tweeter Center and Merriweather Post Pavilion).