Universal chairman and chief executive Lucian Grainge and EMI boss Roger Faxon led the charge, arguing that the deal would benefit the debt-ridden music firm.
Universal believes that despite its increased market share, the real power in the music industry lies with the digital retail giants such as Apple iTunes and Amazon.
But the takeover is being vehemently opposed by rival music giant Warner, which bid unsuccessfully for EMI last year.
Warner claims the deal, which would give the company a market share of above 50 per cent in several countries, would knock the entire music market, from the artist to the consumer. The Senate hearing is not part of the official Federal Trade Commission (FTC) probe, but its outcome could affect the FTC’s decision.