Twitter may try to buy its way out of its growth problem by making another move into music. The company is considering a deal to acquire SoundCloud, the music and audio-sharing company, according to people familiar with both companies. Berlin-based SoundCloud is a free service that lets users upload and share audio files around the Web; it likes to describe itself as the “YouTube for audio.” In October 2013, the company announced that it had 250 million users. If the deal goes forward, and that’s by no means a certainty, it would likely be Twitter’s most expensive acquisition by some margin. Earlier this year, SoundCloud announced a $60 million funding round that valued the company at $700 million. Last fall, as Twitter was preparing to go public, it acquired mobile ad company MoPub in a deal that valued that company above $300 million.