The Boss RC-50 loopstation is supported by midiclock.
The RC-50 can receive MIDI clock from external MIDI devices and perform at the same tempo as (be synchronized with) the external MIDI device (in this case the midiclock application). This enables control of the RC-50 using the same tempo as your other equipment.
Performances are normally played [...]

Synchronizing the Boss GT-10 or GT-10B to midiclock is quite easy.
Simply connect the midi output of your computer to the midi in of the GT 10 and use this output with midiclock.
On your effects pedal, set the “Sync Clock” option in the menu “System Menu/Midi/Setting” to “Auto”,
this enables the receiving of the realtime midi beat [...]

You can easily sync the GT-6, GT-8 or GT-Pro to midiclock :
–> in the unit’s midi menu, set the setting “MIDI Sync Clock” to Auto.

Now it will receive the midi clock signal and set it’s BPM rate accordingly.

Instruments

1.Acc. grand piano
33.Accoustic bass
65.Soprano sax
97.FX rain

2.Bright piano
34.Fingered bass
66.Alto sax
98.FX soundtrack

3.Elec. grand piano
35.Picked bass
67.enor sax
99.FX crystal

4.Honky-tonk piano
36.Fretless bass
68.Baritone sax
100.FX atmosphere

5.Elec. piano 2
37.Slap bass 1
69.Oboe
101.FX brightness

6.Elec piano 1
38.Slap bass 2
70.English horn
102.FX goblins

7.Harpsichord
39.Synth bass 1
71.Bassoon
103.FX echo drops

8.Clavi
40.Synth bass 2
72.Clarinet
104.FX star theme

9.Celesta
41.Violin
73.Piccolo
105.Sitar

10.Glockenspiel
42.Viola
74.Flute
106.Banjo

11.Music box
43.Cello
75.Recorder
107.Shamisen

12.Vibraphone
44.Contrabass
76.Pan flute
108.Koto

13.Marimba
45.Tremolo strings
77.Blown bottle
109.Kalimba

14.Xylophone
46.Pizz. strings
78.Shakuhachi
110.Bagpipe

15.Tubular [...]

MIDIClock can be used to synchronize multiple sequencers/synths.
You can do this using MIDIYoke (get it at www.midiox.com) :
Connect MIDIClock to MIDIYoke Junction 1 output. As MIDIYoke is a multiclient
driver, you can connect multiple sequencers/synths (such as rebirth, AN1x,…)
to MIDIYoke Junction 1 MIDI input.

By editing the clockpresets.ini file, you can achieve even more
advanced remote control of midiclock. Enable HexSpy to monitor the
incoming midi messages. It will help you determine which entries
you need to add to the ini file.
The BPM_PRESETS section contains the tempo settings for all patch selects.
You can add action codes to any of these entries.
Additionally you [...]