| 1931 TRUJO Attachment Stringed Musical Instruments |
| 1931 JOHN HAYS HAMMOND JR Closure Musical Instruments |
| 1931 ALLEN Tuning Wind Musical Instruments Art |
| 1931 OTTO Peg String Musical Instruments Art |
| 1931 PAGE Tailpiece Mute Stringed Musical Instruments |
| 1931 CONN LTD C G Key Spatule Musical Instruments |
| 1931 MA Horn Attachment String Musical Instruments |
| 1931 J C DEAGAN INC Vibrant Bar Musical Instruments |
| 1931 TRENOR Closure Musical Instruments Art |
| 1931 LOGAN Head For Musical Instruments Patent |
| 1931 PAGE Mute Stringed Musical Instruments Art |
| 1931 KURT Chin Rest Violins Similar Musical Instruments |
| 1931 NICOMEDE Support Musical Instruments Art |
| 1931 GRIFFITH Sound Post Stringed Musical Instruments |
| 1931 TRUETT Attachment Stringed Musical Instruments |
| 1931 CONN LTD C G Tuning Wind Musical Instruments |
| 1931 RUSSELL Key Spatule Musical Instruments Art |
| 1931 HENRY Steel Stringed Musical Instruments |
| 1931 HAMMOND Tone Modulator Musical Instruments |
| 1931 EMANUEL Keyboard Musical Instruments Art |
| 1931 ALLEN Tuning Musical Instruments Art Print |
| 1931 CONN LTD C G Tuning Musical Instruments Art |