The first wave of classic Wu-Tang solo albums — Method Man’s Tical, GZA’s Liquid Swords, and Raekwon’s Only Built 4 Cuban Linx — were spare and cerebral. Ghostface Killah’s Ironman brought a burst of unbridled vulnerability to the crew’s aesthetic. Ghostface’s style fuses detail-oriented storytelling with stream-of-consciousness word association, but his delivery has the emotional urgency of a man perpetually on the verge of tears. Brilliant works like “Wildflower,” “Fasta Blade,” “Assassination Day,” Winter Warz” and “Box In Hand” adhere to the Wu-Tang’s spare, mysterious blueprint, but Ironman is defined by its references to ‘70s R&B. Ghostface is perfectly matched to the deconstructed Memphis soul samples of “Iron Maiden,” “260,” “Fish,” and “Motherless Child,” while the drumless Jackson 5 sample used in “All That I Got Is You” sets that song’s poignant tone. Ironman closes with its most overlooked but also most interesting songs. Arranged in a haunting trilogy, “Motherless Child,” “Black Jesus” and “After the Smoke Is Clear” are ruminations that fuse Black Nationalist theology, ghetto portraiture, and ancient blues.