In this bachelor project, Leon Falk has examined the interplay and collective improvisation in New Orleans jazz and related genres - in particular the interplay among the wind instrumentalists in New Orleans jazz and brass bands. The main goal has been to develop as a trombone player and ensemble musician.This reflective thesis includes a description of the process of the project and the exam concert, a historical reflection about the New Orleans jazz and brass band tradition and an analysis of 9 interviews with contemporary musicians playing traditional jazz: Jens "Jesse" Lindgren, Björn Ingelstam, Ulf Johansson Werre, Joakim Falk, Claes Ringqvist, Klas Lindqvist, Hans Ingelstam, Niklas Carlsson and Örjan Kjellin. The thesis ends with a conclusive reflection about the project as a whole and Leon Falk's own play style in ensemble with other wind instruments. / <p><strong>Repertoar examenskonsert: </strong>St James Infirmiry (trad), Room Rent Blues (Irving Newton), At the Georgia Camp Meeting (Kerry Mills), Should I Reveal (Nacio H Brown / Arthur Freed), Savoy Blues (Edward Kid Ory), While We Danced At the Mardi Gras (Alfred M Opler / John H Mercer), Cash is King (Leon Falk), Girl Of My Dreams (Sunny Clapp).<strong>Musiker examenskonert: </strong>Leon Falk (trombon/sång), Adam Falk (klarinett/tenorsaxofon), Erik Tengholm (trumpet/kornett), Jocke Falk (trumpet/kornett), Uno Dvärby (kontrabas/banjo), Sara Karkkonen (piano), Jonathan Leidecker (trummor).</p>