guitars (track 15) Quincy S. Jackson – marketing Jay-Z – songwriting (tracks 4–6 and 12), vocals (tracks 5, 6 and 12) Nathan Jenkins – engineering (track 17) Rodney "Darkchild" Jerkins – horn arrangement (track 12), instrumentation (track 12), mixing (track 12), production (tracks 12 and 16), songwriting (track 12) James Johnson – bass (track 15) Jon Jon – bass (track 12), production assistance (track 12) Ronald Judge – horns (track 12) Suzie Katayama – cello (track 15) Gimel "Young Guru" Keaton – engineering (track 5) Hannah Khoury – viola (track 1), violin (track 1) Kimberly Kimble – hair styling Rob Kinelski – engineering assistance (tracks 1–4, 6 and 9–14) Julia Knapp – A&R operation Mathew Knowles – A&R, executive production, management Solange Knowles – songwriting (tracks 6, 7 and 9) Tina Knowles – styling Henry Krieger – songwriting (track 15) Ricky Lawson – drums (track 15) Jolie Levine – music contracting (track 15) Espen Lind – guitar (track 2), songwriting (track 2) Dave "D-Lo" Lopez – engineering assistance (tracks 14 and 18), mixing assistance (track 18), Pro Tools editing (track 14) Riley Mackin – engineering assistance (track 15) Manny Marroquin – mixing (track 15) Harvey Mason Jr. – percussion (track 15) Curtis Mayfield – songwriting (track 14) Vlado Meller – mastering (track 18) Chuck Middleton – songwriting (track 11) Colin Miller – digital prep engineering (tracks 7 and 8), mixing assistance (track 1), Pro Tools prep (track 16) Walter W. "Lil Walt" Millsap III – engineering (track 14), instrumentation (track 14), Pro Tools editing (track 14), production (track 14), songwriting (track 14) MK – songwriting (track 6) Mo Horns – horns (track 16) Naser Musa – oud (track 1) Candice "G.G." Nelson – instrumentation (track 14), production (track 14), songwriting (track 14) The Neptunes – production (tracks 3 and 4) Sara Parkins – violin (track 15) Dave "Hard Drive" Pensado – mixing (track 17) Rudy Pérez – arrangement (track 18), backing vocals (track 18), keyboards (track 18), production (track 18), programming (track 18), Spanish guitar (track 18), vocal direction (track 18), vocal production (track 1) Clay Perry – engineering (track 18), keyboards (track 18), Pro Tools editing (track 18), programming (track 18) Denaun Porter – programming (track 1) Anne Preven – songwriting (track 15) Keli Nicole Price – songwriting (track 12) Boujemaa Razgui – ney (track 1) Clarence Reid – songwriting (track 6) Aaron Renner – engineering (track 15) Geoff