art direction Lynn Dreese Breslin
composed by Edgard Varèse
conductor Frederic Waldman
lacquer cut by George Piros
liner notes Frank Zappa
liner notes Ilhan Mimaroglu
liner notes [on jack skurnick and ems records] Emanuel Levenson
liner notes [original release] Sidney Finkelstein
mastered by George Piros
orchestra New York Wind Ensemble
percussion Juilliard Percussion Orchestra
photography by [cover] Ilhan Mimaroglu
recorded by Robert E. Blake
Distributed By Atlantic Recording Corporation
Phonographic Copyright (p) Finnadar Records
Copyright (c) Finnadar Records
Lacquer Cut At Atlantic Studios
Pressed By Specialty Records Corporation
℗ © 1977 Finnadar Records.

Recorded in New York City in 1950. 'Density 21.5' on May 11 at Rachmaninoff Society; 'Ionisation' on May 21 at Greenwich House Music School; 'Octandre' and 'Intégrales' on June 21 at The Mannes College of Music.

The EMS album (401) containing the above selections was first released on October 1st, 1950.

'Interpolations' are 'organized sound' compositions on magnetic tape, realized in 1954 in the studios of the Groupe de Musique Concrète, Club d'Essai, RTF, Paris, France. This original version is previously unreleased on recordings.

From the original mono master tapes, except 'Interpolations' which are in stereo.

Cover photo is dated 1955.
Matrix / Runout: STX 157-P (Runout Side A, etched, variant 1)
Matrix / Runout: STX 158-P (Runout Side B, etched, variant 1)
Matrix / Runout: STX-157 C SP @tGP 1-2 (Runout Side A, etched, variant 2)
Matrix / Runout: 1-1 ST-X-158-B @tGP SRC (Runout Side B, etched, exc. SRC logo, stamped, variant 2)