When Cuba Gooding, Sr. passed away in April 2017, it marked the true end of an era for the venerable soul group The Main Ingredient.  The Harlem-founded group had endured tragedy, personnel shifts, and the changing sound of music to prosper for decades, but the heart of the Main Ingredient remains in the group’s RCA recordings.  The recent 2-CD collection from Cherry Red’s SoulMusic Records imprint, Brotherly Love: The RCA Anthology, brings together 41 tracks originally issued between 1970 and 1981 on the venerable label. Friends Donald McPherson, Luther Simmons, and Tony…