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I was listening to Hikawa Kiyoshi's ソーラン節 and instead of 浴びる he said 浴びりゃ， is there a normal pattern for this kind of pronunciation? Is it regional?
Song lyrics tend to take poetic license, but if not, this is a shortening of 「浴びれば」. As far as I'm aware, it's not regional, since I hear it in common speech in Tokyo and on television programs.