Johannes Brahms had a formidable beard, but behind it beat the heart of a poet. His horn trio begins with a sigh, and then takes you closer to the composer’s inmost soul than almost anything he wrote. The gorgeous Clarinet Quintet seems to swirl into existence out of thin air; but before long these five musicians are uncovering the deepest secrets and the most passionate imaginings of music’s ultimate romantic dreamer. A team of RSNO players gets up close and personal today.