The phrase "a cd playing" is correct and usable in written English.
It can be used to describe the action of a CD currently being played in a device.
Example: "I love the sound of a CD playing in the background while I work."
Alternatives: "a CD in use" or "a CD that is playing".
Beyoncé asked Frank Ocean to write and record "I Miss You" at MSR, saying to Complex, "[Jay-Z] had a CD playing in the car one Sunday when we were driving to Brooklyn.
She subsequently invited Ocean to co-write "I Miss You" for her album 4. Discussing how she first heard of Ocean and Nostalgia, Ultra, she commented; "Jay-Z had a CD playing in the car one Sunday when we were driving to Brooklyn.
If time were to stop right now, the past couple weeks would be near the top of the highlight reel for my short time on earth [sic]." In July 2011, Knowles sat for an interview with Gabriel Alvarez of Complex magazine, where she elaborated on how she came to know about Ocean: "Jay[-Z] had a CD playing in the car one Sunday when we were driving to Brooklyn.
This involves an assessor sitting quietly and unobtrusively at the back of the room, with a CD playing into a headphone whilst observing the programme.
Music for the tenor trombone, however, is usually notated in concert pitch (that is, a C played on the trombone is the same note as the C on a piano).
"Where are you?" he asks, hearing a Michel Camilo cd playing in the background.
The MHC class Ia molecules, including human leukocyte antigen (HLA -A, B, and C, play a central role in adaptive immunity.
The a-C coating plays a significant role in the tensile strength, and fracture energy of the nanocomposites.
This a-C layer plays a crucial role in determining baseline resistance and the sensitivity, since it affects the current path.
Conclusions: Our data provide evidence that an ECM glycoprotein component, tenascin-C, plays a relevant role in hematopoiesis through interaction between stromal cells and hematopoietic progenitor cells.
We also know that the wave speed c plays a critical role in a physical structure of the solutions for the combined ZK-mZK equation.
