Select > Track Start to Cursor

`Shift` + `J`

All hotkeys for Audacity 2 (Windows)

File Menu New	`Ctrl` + `N`
File Menu Open	`Ctrl` + `O`
File Menu Close	`Ctrl` + `W`
File Menu Save	`Ctrl` + `V`
File Menu Import audio	`Ctrl` + `Shift` + `I`
File Menu Export audio	`Ctrl` + `Shift` + `E`
File Menu Export multiple	`Ctrl` + `Shift` + `L`
File Menu Exit	`Ctrl` + `Q`
Edit Menu Undo	`Ctrl` + `Z`
Edit Menu Redo	`Ctrl` + `Y`
Edit Menu Cut	`Ctrl` + `X`
Edit Menu Delete	`Ctrl` + `K`
Edit Menu Remove special> Split cut	`Ctrl` + `Alt` + `X`
Edit Menu Remove special> Split delete	`Ctrl` + `Alt` + `K`
Edit Menu Remove special> Silence audio	`Ctrl` + `L`
Edit Menu Remove special> Time audio	`Ctrl` + `T`
Edit Menu Clip Boundaries > Split	`Ctrl` + `I`
Edit Menu Clip Boundaries > Split New	`Ctrl` + `Alt` + `I`
Edit Menu Clip Boundaries > Join	`Ctrl` + `J`
Edit Menu Clip boundaries > detach at silence	`Ctrl` + `Alt` + `J`
Edit Menu Copy	`Ctrl` + `C`
Edit Menu Paste	`Ctrl` + `V`
Edit Menu Paste text as new label	`Ctrl` + `Alt` + `V`
Edit Menu Duplicate	`Ctrl` + `D`
Edit Menu Labeled audio > cut	`Alt` + `X`
Edit Menu Labeled audio > Delete	`Alt` + `K`
Edit Menu Labeled audio >split cut	`Shift` + `Alt` + `X`
Edit Menu Labeled audio >split delete	`Shift` + `Alt` + `K`
Edit Menu Labeled audio >silence audio	`Alt` + L`
Edit Menu Labeled audio >copy	`Shift` + `Alt` + `C`
Edit Menu Labeled audio >split	`Alt` + `I`
Edit Menu Labeled audio >join	`Alt` + `J`
Edit Menu Labeled audio >detach at silences	`Ctrl` + `Alt` + `A`
Edit Menu Select all	`Ctrl` + `A`
Edit Menu Select none	`Ctrl` + `SHift` + `A`
Edit Menu Select > Spectral > Toggle Spectral Selection	`Q`
Edit Menu Select > Left at Playback Position	`[`
Edit Menu Select > right at Playback Position	`]`
Edit Menu Select > Track Start to Cursor	`Shift` + `J`
Edit Menu Select > Cursor to Track End	`Shift` + `K`
Edit Menu Select > In All Tracks	`Ctrl` + `Shift` + `K`
Edit Menu Select > In All Sync-Locked Tracks	`Ctrl` + `Shift` + `Y`
Edit Menu FInd zero crossings	`Z`
Edit Menu Move cursor to selection start	`Left`
Edit Menu Move cursor to selection end	`Right`
Edit Menu Move cursor to track start	`J`
Edit Menu Move cursor to track end	`K`
Edit Menu Move to and open next label	`Tab`
Edit Menu Preferences	`Ctrl` + `P`
Edit Menu Move to and open previous label	`Shift` + `Tab`
Edit Menu Move to previous label	`Alt` + `Right`
Edit Menu Move to next label	`Alt` + `Left`
Edit Menu Selection to start	`Shift` + `Home`
Edit Menu Selection to end	`Shift` + `End`
Edit Menu Delete key	`Backspace`
Edit Menu Delete key 2	`Delete`
Edit Menu Selection extend left	`Shift` + `Left`
Edit Menu Selection extend right	`Shift` + `Right`
Edit Menu Selection contract left	`Ctrl` + `Shift` + `Left`
Edit Menu Selection contract right	`Ctrl` + `Shift` + `Right`
Edit Menu Cursor left	`Left`
Edit Menu Cursor right	`Right`
Edit Menu Cursor Short Jump Left	`,`
Edit Menu Cursor Short Jump right	`.`
Edit Menu Cursor long Jump Left	`Shift` + `,`
Edit Menu Cursor long Jump right	`Shift` + `.`
View Menu Zoom in	`Ctrl` + `1`
View Menu Zoom normal	`Ctrl` + `2`
View Menu Zoom out	`Ctrl` + `3`
View Menu Zoom to selection	`Ctrl` + `E`
View Menu Fit in window	`Ctrl` + `F`
View Menu Fit vertically	`Ctrl` + `Shift` + `F`
View Menu Go to selection start	`Ctrl` + `[`
View Menu Go to selection end	`Ctrl` + `]`
View Menu Collapse all tracks	`Ctrl` + `Shift` + `C`
View Menu Expand collapsed tracks	`Ctrl` + `Shift` + `X`
View Menu Full screen on/off	`F11`
Transport Menu Play/stop	`Space`
Transport Menu Play/stop and set cursor	`X`
Transport Menu Loop play	`Shift` + `Space`
Transport Menu Pause	`P`
Transport Menu Skip to start	`Home`
Transport Menu Skip to end	`End`
Transport Menu Record	`R`
Transport Menu Timer record	`Shift` + `T`
Transport Menu Append record	`Shift` + `R`
Transport Menu Move cursor to next label	`Alt` + `Right`
Transport Menu Move cursor to previous label	`Alt` + `Left`
Transport Menu Play one second	`1`
Transport Menu Play to selection	`B`
Transport Menu Play cut preview	`C`
Transport Menu Play short period before selection start	`Shift` + `F5`
Transport Menu Play short period after selection start	`Shift` + `F6`
Transport Menu Play short period before selection end	`Shift` + `F7`
Transport Menu Play short period after selection end	`Shift` + `F8`
Transport Menu Play short period before and after selection start	`Ctrl` + `Shift` + `F5`
Transport Menu Play short period before and after selection end	`Ctrl` + `Shift` + `F7`
Transport Menu Short Seek Left during Playback	`Left` / `,`
Transport Menu Short Seek right during Playback	`Right` / `.`
Transport Menu Long Seek Left during Playback	`Shift` + `Left`
Transport Menu Long Seek Right during Playback	`Shift` + `Right`
Effect Menu Repeat last effect	`Ctrl` + `R`
Analyse Menu Contrast	`Ctrl` + `Shift` + `T`
Device Toolbar Change Audio Host	`Shift` + `N`
Device Toolbar Change Playback Device	`Shift` + `O`
Device Toolbar Change Recording Device	`Shift` + `I`
Device Toolbar Change Recording Channels	`Shift` + `N`
Tools Toolbar Selection tool	`F1`
Tools Toolbar Envelope tool	`F2`
Tools Toolbar Draw tool	`F3`
Tools Toolbar Zoom tool	`F4`
Tools Toolbar Time shift tool	`F5`
Tools Toolbar Multi-tool	`F6`
Tools Toolbar Next-tool	`D`
Tools Toolbar Previous tool	`A`
Keyboard Focus Move backward through currently focused toolbar in Upper Toolbar dock area	`Ctrl` + `Shift` + `F6`
Keyboard Focus Move forward through currently focused toolbar in Upper Toolbar dock area	`Ctrl` + `F6`
Keyboard Focus Move backward through modeless windows	`Alt` + `Shift` + `F6`
Keyboard Focus Move forward through modeless windows	`Alt` + `F6`
Audio Track Dropdown Menu Open menu on focused track	`Shift` + `M`
Audio Track Dropdown Menu Mute/Unmute focused track	`Shift` + `U`
Audio Track Dropdown Menu Solo/Unsolo focused track	`Shift` + `S`
Audio Track Dropdown Menu Change gain on focused track	`Shift` + `G`
Audio Track Dropdown Menu Increase gain on focused track	`Alt` + `Shift` + `Up`
Audio Track Dropdown Menu Decrease gain on focused track	`Alt` + `Shift` + `Down`
Audio Track Dropdown Menu Pan left on focused track	`Alt` + `Shift` + `Left`
Audio Track Dropdown Menu Pan right on focused track	`Alt` + `Shift` + `Right`
Audio Track Dropdown Menu Change pan on focused track	`Shift` + `P`