In the wake of Irving Azoff’s exit at the end of last year, Madison Square Garden chief and noted bluesman James Dolan has resigned from the Live Nation board, with the company pondering a sell-off of its shares in the live concert promotion and management monolith. MSG’s 3.9 million shares, which represent about 2% of the company’s stock, are worth about $40 million before taxes. Dolan’s resignation was announced in a filing by Live Nation yesterday. Madison Square Garden acquired its stake as part of a transaction Live Nation completed in February 2011, when it bought the remaining 25% of Azoff’s Front Line Management Group that it didn’t already own. [HitsDailyDouble]